diff --git a/.editorconfig b/.editorconfig
index 3a8bbb3..263f643 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -1,4 +1,8 @@
-[*.cs]
+[*]
+indent_style = space
+indent_size = 4
+
+[*.cs]
 
 # CA1810: Initialize reference type static fields inline
 dotnet_diagnostic.CA1810.severity = none
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..42c2659
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+.vs
+/LibgenDesktop.Setup/obj
+/LibgenDesktop/bin
+/LibgenDesktop/obj
+/packages
diff --git a/LibgenDesktop/Common/Constants.cs b/LibgenDesktop/Common/Constants.cs
index 1b8f9bf..3907c1c 100644
--- a/LibgenDesktop/Common/Constants.cs
+++ b/LibgenDesktop/Common/Constants.cs
@@ -27,6 +27,7 @@ internal static class Constants
         public const int NON_FICTION_GRID_AUTHORS_COLUMN_MIN_WIDTH = 150;
         public const int NON_FICTION_GRID_SERIES_COLUMN_MIN_WIDTH = 150;
         public const int NON_FICTION_GRID_YEAR_COLUMN_MIN_WIDTH = 60;
+        public const int NON_FICTION_GRID_IDENTIFIER_COLUMN_MIN_WIDTH = 150;
         public const int NON_FICTION_GRID_LANGUAGE_COLUMN_MIN_WIDTH = 150;
         public const int NON_FICTION_GRID_PUBLISHER_COLUMN_MIN_WIDTH = 150;
         public const int NON_FICTION_GRID_FORMAT_COLUMN_MIN_WIDTH = 80;
@@ -95,6 +96,7 @@ internal static class Constants
         public const int DEFAULT_NON_FICTION_GRID_AUTHORS_COLUMN_WIDTH = 200;
         public const int DEFAULT_NON_FICTION_GRID_SERIES_COLUMN_WIDTH = 180;
         public const int DEFAULT_NON_FICTION_GRID_YEAR_COLUMN_WIDTH = 60;
+        public const int DEFAULT_NON_FICTION_GRID_IDENTIFIER_COLUMN_WIDTH = 180;
         public const int DEFAULT_NON_FICTION_GRID_LANGUAGE_COLUMN_WIDTH = 180;
         public const int DEFAULT_NON_FICTION_GRID_PUBLISHER_COLUMN_WIDTH = 180;
         public const int DEFAULT_NON_FICTION_GRID_FORMAT_COLUMN_WIDTH = 100;
diff --git a/LibgenDesktop/Models/Localization/Localizators/SearchResultGrids/NonFictionSearchResultsGridColumnsLocalizator.cs b/LibgenDesktop/Models/Localization/Localizators/SearchResultGrids/NonFictionSearchResultsGridColumnsLocalizator.cs
index 37a15f7..bb035ee 100644
--- a/LibgenDesktop/Models/Localization/Localizators/SearchResultGrids/NonFictionSearchResultsGridColumnsLocalizator.cs
+++ b/LibgenDesktop/Models/Localization/Localizators/SearchResultGrids/NonFictionSearchResultsGridColumnsLocalizator.cs
@@ -11,6 +11,7 @@ public NonFictionSearchResultsGridColumnsLocalizator(List<Translation> prioritiz
             Authors = Format(section => section?.Authors);
             Series = Format(section => section?.Series);
             Year = Format(section => section?.Year);
+            Identifier = Format(section => section?.Identifier);
             Language = Format(section => section?.Language);
             Publisher = Format(section => section?.Publisher);
             FormatColumn = Format(section => section?.Format);
@@ -23,6 +24,7 @@ public NonFictionSearchResultsGridColumnsLocalizator(List<Translation> prioritiz
         public string Authors { get; }
         public string Series { get; }
         public string Year { get; }
+        public string Identifier { get; }
         public string Language { get; }
         public string Publisher { get; }
         public string FormatColumn { get; }
diff --git a/LibgenDesktop/Models/Localization/Translation.cs b/LibgenDesktop/Models/Localization/Translation.cs
index 4a8d054..8eb7951 100644
--- a/LibgenDesktop/Models/Localization/Translation.cs
+++ b/LibgenDesktop/Models/Localization/Translation.cs
@@ -275,6 +275,7 @@ internal class NonFictionSearchResultsGridColumnsTranslation
             public string Authors { get; set; }
             public string Series { get; set; }
             public string Year { get; set; }
+            public string Identifier { get; set; }
             public string Language { get; set; }
             public string Publisher { get; set; }
             public string Format { get; set; }
diff --git a/LibgenDesktop/Models/Settings/AppSettings.cs b/LibgenDesktop/Models/Settings/AppSettings.cs
index 165c1b3..0e020c7 100644
--- a/LibgenDesktop/Models/Settings/AppSettings.cs
+++ b/LibgenDesktop/Models/Settings/AppSettings.cs
@@ -100,6 +100,7 @@ public static NonFictionColumnSettings Default
                         AuthorsColumnWidth = DEFAULT_NON_FICTION_GRID_AUTHORS_COLUMN_WIDTH,
                         SeriesColumnWidth = DEFAULT_NON_FICTION_GRID_SERIES_COLUMN_WIDTH,
                         YearColumnWidth = DEFAULT_NON_FICTION_GRID_YEAR_COLUMN_WIDTH,
+                        IdentifierColumnWidth = DEFAULT_NON_FICTION_GRID_IDENTIFIER_COLUMN_WIDTH,
                         LanguageColumnWidth = DEFAULT_NON_FICTION_GRID_LANGUAGE_COLUMN_WIDTH,
                         PublisherColumnWidth = DEFAULT_NON_FICTION_GRID_PUBLISHER_COLUMN_WIDTH,
                         FormatColumnWidth = DEFAULT_NON_FICTION_GRID_FORMAT_COLUMN_WIDTH,
@@ -114,6 +115,7 @@ public static NonFictionColumnSettings Default
             public int AuthorsColumnWidth { get; set; }
             public int SeriesColumnWidth { get; set; }
             public int YearColumnWidth { get; set; }
+            public int IdentifierColumnWidth { get; set; }
             public int LanguageColumnWidth { get; set; }
             public int PublisherColumnWidth { get; set; }
             public int FormatColumnWidth { get; set; }
diff --git a/LibgenDesktop/Resources/Languages/English.lng b/LibgenDesktop/Resources/Languages/English.lng
index 27da70e..fda097d 100644
--- a/LibgenDesktop/Resources/Languages/English.lng
+++ b/LibgenDesktop/Resources/Languages/English.lng
@@ -241,6 +241,7 @@
             "Authors": "Authors",
             "Series": "Series",
             "Year": "Year",
+            "Identifier": "Identifier",
             "Language": "Language",
             "Publisher": "Publisher",
             "Format": "Format",
diff --git a/LibgenDesktop/Styles/Tabs/NonFictionSearchResults.xaml b/LibgenDesktop/Styles/Tabs/NonFictionSearchResults.xaml
index 6f647a8..afbe286 100644
--- a/LibgenDesktop/Styles/Tabs/NonFictionSearchResults.xaml
+++ b/LibgenDesktop/Styles/Tabs/NonFictionSearchResults.xaml
@@ -14,6 +14,8 @@
     <Style x:Key="YearColumnStyle" TargetType="TextBlock" BasedOn="{StaticResource SearchResultsDataGridTextColumnElementStyle}">
         <Setter Property="HorizontalAlignment" Value="Center" />
     </Style>
+    <Style x:Key="IdentifierHeaderStyle" TargetType="DataGridColumnHeader" BasedOn="{StaticResource SearchResultsDataGridLeftAlignedTextHeaderStyle}" />
+    <Style x:Key="IdentifierColumnStyle" TargetType="TextBlock" BasedOn="{StaticResource SearchResultsDataGridTextColumnElementStyle}" />
     <Style x:Key="LanguageHeaderStyle" TargetType="DataGridColumnHeader" BasedOn="{StaticResource SearchResultsDataGridLeftAlignedTextHeaderStyle}" />
     <Style x:Key="LanguageColumnStyle" TargetType="TextBlock" BasedOn="{StaticResource SearchResultsDataGridTextColumnElementStyle}" />
     <Style x:Key="PublisherHeaderStyle" TargetType="DataGridColumnHeader" BasedOn="{StaticResource SearchResultsDataGridLeftAlignedTextHeaderStyle}" />
diff --git a/LibgenDesktop/ViewModels/SearchResultItems/NonFictionSearchResultItemViewModel.cs b/LibgenDesktop/ViewModels/SearchResultItems/NonFictionSearchResultItemViewModel.cs
index 756a500..8d5581f 100644
--- a/LibgenDesktop/ViewModels/SearchResultItems/NonFictionSearchResultItemViewModel.cs
+++ b/LibgenDesktop/ViewModels/SearchResultItems/NonFictionSearchResultItemViewModel.cs
@@ -1,14 +1,50 @@
-using System.Collections.ObjectModel;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using LibgenDesktop.Models.Entities;
 using LibgenDesktop.Models.Localization;
 
 namespace LibgenDesktop.ViewModels.SearchResultItems
 {
+    internal class GroupingByIdentifier
+    {
+        protected Dictionary<string, int> mapUnqiqueID = new Dictionary<string, int>();
+        protected int lastId = 1;
+
+        public int GetId(NonFictionBook book)
+        {
+            if (string.IsNullOrEmpty(book.IdentifierPlain?.Trim()))
+                return 0;
+
+            string[] ids = book.IdentifierPlain.Split(',');
+            int resId = lastId;
+            foreach (var id in ids)
+            {
+                string id1 = id.Trim();
+                int uniqueId;
+                if (mapUnqiqueID.TryGetValue(id1, out uniqueId))
+                {
+                    resId = uniqueId;
+                    break;
+                }
+            }
+            if (resId == lastId)
+                ++lastId;
+            foreach (var id in ids)
+            {
+                string id1 = id.Trim();
+                if (!mapUnqiqueID.ContainsKey(id1))
+                    mapUnqiqueID[id1] = resId;
+            }
+            return resId;
+        }
+    }
+
     internal class NonFictionSearchResultItemViewModel : SearchResultItemViewModel<NonFictionBook>
     {
-        public NonFictionSearchResultItemViewModel(NonFictionBook book, LanguageFormatter formatter)
+        public NonFictionSearchResultItemViewModel(NonFictionBook book, LanguageFormatter formatter, GroupingByIdentifier grouping)
             : base(book, formatter)
         {
+            GroupId = grouping.GetId(book);
         }
 
         public NonFictionBook Book => LibgenObject;
@@ -16,6 +52,8 @@ public NonFictionSearchResultItemViewModel(NonFictionBook book, LanguageFormatte
         public string Authors => Book.Authors;
         public string Series => Book.Series;
         public string Year => Book.Year;
+        public string Identifier => Book.Identifier;
+        public int GroupId { get; set; }
         public string Language => Book.Language;
         public string Publisher => Book.Publisher;
         public string Format => Book.Format;
diff --git a/LibgenDesktop/ViewModels/Tabs/NonFictionSearchResultsTabViewModel.cs b/LibgenDesktop/ViewModels/Tabs/NonFictionSearchResultsTabViewModel.cs
index fc721d2..cbfe992 100644
--- a/LibgenDesktop/ViewModels/Tabs/NonFictionSearchResultsTabViewModel.cs
+++ b/LibgenDesktop/ViewModels/Tabs/NonFictionSearchResultsTabViewModel.cs
@@ -30,10 +30,11 @@ public NonFictionSearchResultsTabViewModel(MainModel mainModel, IWindowContext p
             List<NonFictionBook> searchResults)
             : base(mainModel, parentWindowContext, LibgenObjectType.NON_FICTION_BOOK, searchQuery)
         {
+            GroupingByIdentifier grouping = new GroupingByIdentifier();
             columnSettings = mainModel.AppSettings.NonFiction.Columns;
             LanguageFormatter formatter = MainModel.Localization.CurrentLanguage.Formatter;
             books = new ObservableCollection<NonFictionSearchResultItemViewModel>(searchResults.Select(book =>
-                new NonFictionSearchResultItemViewModel(book, formatter)));
+                new NonFictionSearchResultItemViewModel(book, formatter, grouping)));
             Initialize();
         }
 
@@ -111,6 +112,18 @@ public int YearColumnWidth
             }
         }
 
+        public int IdentifierColumnWidth
+        {
+            get
+            {
+                return columnSettings.IdentifierColumnWidth;
+            }
+            set
+            {
+                columnSettings.IdentifierColumnWidth = value;
+            }
+        }
+
         public int LanguageColumnWidth
         {
             get
@@ -232,8 +245,9 @@ protected override async Task SearchAsync(string searchQuery, CancellationToken
                 ShowErrorWindow(exception, ParentWindowContext);
             }
             LanguageFormatter formatter = MainModel.Localization.CurrentLanguage.Formatter;
+            GroupingByIdentifier grouping = new GroupingByIdentifier();
             Books = new ObservableCollection<NonFictionSearchResultItemViewModel>(result.Select(book =>
-                new NonFictionSearchResultItemViewModel(book, formatter)));
+                new NonFictionSearchResultItemViewModel(book, formatter, grouping)));
             UpdateBookCount();
             IsSearchResultsGridVisible = true;
             IsStatusBarVisible = true;
diff --git a/LibgenDesktop/Views/Tabs/NonFictionSearchResultsTab.xaml b/LibgenDesktop/Views/Tabs/NonFictionSearchResultsTab.xaml
index 7999140..8a34282 100644
--- a/LibgenDesktop/Views/Tabs/NonFictionSearchResultsTab.xaml
+++ b/LibgenDesktop/Views/Tabs/NonFictionSearchResultsTab.xaml
@@ -15,6 +15,13 @@
             <RowDefinition />
             <RowDefinition Height="Auto" />
         </Grid.RowDefinitions>
+        <Grid.Resources>
+            <CollectionViewSource x:Key="cvsBooks" Source="{Binding Books}">
+                <CollectionViewSource.GroupDescriptions>
+                    <PropertyGroupDescription PropertyName="GroupId"/>
+                </CollectionViewSource.GroupDescriptions>
+            </CollectionViewSource>
+        </Grid.Resources>
         <Grid Grid.Row="0">
             <Grid.ColumnDefinitions>
                 <ColumnDefinition />
@@ -56,7 +63,7 @@
                     ToolTip="{Binding Localization.ExportButtonTooltip}"
                     IsEnabled="{Binding IsExportPanelVisible, Converter={StaticResource booleanInverseConverter}}" />
         </Grid>
-        <c:BookDataGrid x:Name="bookGrid" Grid.Row="1" ItemsSource="{Binding Books, IsAsync=True}"
+        <c:BookDataGrid x:Name="bookGrid" Grid.Row="1" ItemsSource="{Binding Source={StaticResource cvsBooks}, IsAsync=True}"
                         SelectedRows="{Binding SelectedRows, Mode=OneWayToSource}"
                         Visibility="{Binding IsSearchResultsGridVisible, Converter={StaticResource booleanToCollapsedConverter}}"
                         Style="{StaticResource BookDataGrid}">
@@ -70,6 +77,31 @@
                     <Setter Property="ContextMenu" Value="{StaticResource dataGridRowMenu}" />
                 </Style>
             </DataGrid.RowStyle>
+            <DataGrid.GroupStyle>
+                <GroupStyle>
+                    <GroupStyle.ContainerStyle>
+                        <Style TargetType="{x:Type GroupItem}">
+                            <Setter Property="Margin" Value="0,0,0,5"/>
+                            <Setter Property="Template">
+                                <Setter.Value>
+                                    <ControlTemplate TargetType="{x:Type GroupItem}">
+                                        <Expander IsExpanded="True" BorderBrush="#FF002255" BorderThickness="1,1,1,3">
+                                            <Expander.Header>
+                                                <DockPanel>
+                                                    <TextBlock FontWeight="Bold" Text="{Binding Path=Name}" Margin="5,0,0,0"/>
+                                                </DockPanel>
+                                            </Expander.Header>
+                                            <Expander.Content>
+                                                <ItemsPresenter />
+                                            </Expander.Content>
+                                        </Expander>
+                                    </ControlTemplate>
+                                </Setter.Value>
+                            </Setter>
+                        </Style>
+                    </GroupStyle.ContainerStyle>
+                </GroupStyle>
+            </DataGrid.GroupStyle>
             <DataGrid.InputBindings>
                 <KeyBinding Command="{Binding OpenDetailsCommand}" Key="Enter" />
             </DataGrid.InputBindings>
@@ -94,6 +126,11 @@
                                     Width="{Binding DataContext.YearColumnWidth, Source={StaticResource dataGridViewModel}, Converter={StaticResource dataGridLengthConverter}, Mode=TwoWay}"
                                     MinWidth="{Binding Source={x:Static const:Constants.NON_FICTION_GRID_YEAR_COLUMN_MIN_WIDTH}}"
                                     HeaderStyle="{StaticResource YearHeaderStyle}" ElementStyle="{StaticResource YearColumnStyle}" />
+                <DataGridTextColumn Binding="{Binding Identifier}"
+                                    Header="{Binding DataContext.Localization.Columns.Identifier, Source={StaticResource dataGridViewModel}}"
+                                    Width="{Binding DataContext.IdentifierColumnWidth, Source={StaticResource dataGridViewModel}, Converter={StaticResource dataGridLengthConverter}, Mode=TwoWay}"
+                                    MinWidth="{Binding Source={x:Static const:Constants.NON_FICTION_GRID_IDENTIFIER_COLUMN_MIN_WIDTH}}"
+                                    HeaderStyle="{StaticResource IdentifierHeaderStyle}" ElementStyle="{StaticResource IdentifierColumnStyle}" />
                 <DataGridTextColumn Binding="{Binding Language}"
                                     Header="{Binding DataContext.Localization.Columns.Language, Source={StaticResource dataGridViewModel}}"
                                     Width="{Binding DataContext.LanguageColumnWidth, Source={StaticResource dataGridViewModel}, Converter={StaticResource dataGridLengthConverter}, Mode=TwoWay}"