diff --git a/tests/AnthropicClient.Tests/Unit/Json/CitationConverterTests.cs b/tests/AnthropicClient.Tests/Unit/Json/CitationConverterTests.cs
new file mode 100644
index 0000000..2f7fb5f
--- /dev/null
+++ b/tests/AnthropicClient.Tests/Unit/Json/CitationConverterTests.cs
@@ -0,0 +1,14 @@
+namespace AnthropicClient.Tests.Unit.Json;
+
+public class CitationConverterTests : SerializationTest
+{
+  [Fact]
+  public void JsonDeserialization_WhenTypeIsUnknown_ItThrowException()
+  {
+    var json = @"{ ""type"": ""unknown"" }";
+
+    var action = () => Deserialize<Citation>(json);
+
+    action.Should().Throw<JsonException>();
+  }
+}
\ No newline at end of file
diff --git a/tests/AnthropicClient.Tests/Unit/Models/CharacterLocationCitationTests.cs b/tests/AnthropicClient.Tests/Unit/Models/CharacterLocationCitationTests.cs
index 0043ea4..397c572 100644
--- a/tests/AnthropicClient.Tests/Unit/Models/CharacterLocationCitationTests.cs
+++ b/tests/AnthropicClient.Tests/Unit/Models/CharacterLocationCitationTests.cs
@@ -1,7 +1,16 @@
 namespace AnthropicClient.Tests.Unit.Models;
 
-public class CharacterLocationCitationTests
+public class CharacterLocationCitationTests : SerializationTest
 {
+  private readonly string _testJson = @"{
+    ""type"": ""char_location"",
+    ""cited_text"": ""cited text"",
+    ""document_index"": 1,
+    ""document_title"": ""document title"",
+    ""start_char_index"": 2,
+    ""end_char_index"": 3
+  }";
+
   [Fact]
   public void Constructor_WhenCalled_ItShouldSetProperties()
   {
@@ -14,4 +23,36 @@ public class CharacterLocationCitationTests
     result.StartCharIndex.Should().Be(0);
     result.EndCharIndex.Should().Be(0);
   }
+
+  [Fact]
+  public void JsonSerialization_WhenSerialized_ItShouldHaveExpectedShape()
+  {
+    var citation = new CharacterLocationCitation
+    {
+      Type = "char_location",
+      CitedText = "cited text",
+      DocumentIndex = 1,
+      DocumentTitle = "document title",
+      StartCharIndex = 2,
+      EndCharIndex = 3
+    };
+
+    var result = Serialize<Citation>(citation);
+
+    JsonAssert.Equal(_testJson, result);
+  }
+
+  [Fact]
+  public void JsonDeserialization_WhenDeserialized_ItShouldHaveExpectedShape()
+  {
+    var citation = Deserialize<Citation>(_testJson);
+
+    var characterLocationCitation = citation.As<CharacterLocationCitation>();
+    characterLocationCitation!.Type.Should().Be("char_location");
+    characterLocationCitation.CitedText.Should().Be("cited text");
+    characterLocationCitation.DocumentIndex.Should().Be(1);
+    characterLocationCitation.DocumentTitle.Should().Be("document title");
+    characterLocationCitation.StartCharIndex.Should().Be(2);
+    characterLocationCitation.EndCharIndex.Should().Be(3);
+  }
 }
\ No newline at end of file
diff --git a/tests/AnthropicClient.Tests/Unit/Models/CitationDeltaTests.cs b/tests/AnthropicClient.Tests/Unit/Models/CitationDeltaTests.cs
index 8352ce8..2f6d691 100644
--- a/tests/AnthropicClient.Tests/Unit/Models/CitationDeltaTests.cs
+++ b/tests/AnthropicClient.Tests/Unit/Models/CitationDeltaTests.cs
@@ -1,7 +1,19 @@
 namespace AnthropicClient.Tests.Unit.Models;
 
-public class CitationDeltaTests
+public class CitationDeltaTests : SerializationTest
 {
+  private readonly string _testJson = @"{
+    ""type"": ""citations_delta"",
+    ""citation"": {
+      ""type"": ""content_block_location"",
+      ""cited_text"": ""cited text"",
+      ""document_index"": 1,
+      ""document_title"": ""document title"",
+      ""start_block_index"": 2,
+      ""end_block_index"": 3
+    }
+  }";
+
   [Fact]
   public void Constructor_WhenCalled_ItShouldSetProperties()
   {
@@ -28,4 +40,39 @@ public class CitationDeltaTests
 
     act.Should().Throw<ArgumentNullException>();
   }
+
+  [Fact]
+  public void JsonSerialization_WhenSerialized_ItShouldHaveExpectedShape()
+  {
+    var citation = new ContentBlockLocationCitation
+    {
+      Type = "content_block_location",
+      CitedText = "cited text",
+      DocumentIndex = 1,
+      DocumentTitle = "document title",
+      StartBlockIndex = 2,
+      EndBlockIndex = 3
+    };
+
+    var citationDelta = new CitationDelta(citation);
+    var result = Serialize<ContentDelta>(citationDelta);
+
+    JsonAssert.Equal(_testJson, result);
+  }
+
+  [Fact]
+  public void JsonDeserialization_WhenDeserialized_ItShouldHaveExpectedShape()
+  {
+    var citation = Deserialize<ContentDelta>(_testJson);
+
+    var citationDelta = citation.As<CitationDelta>();
+    citationDelta!.Type.Should().Be("citations_delta");
+
+    var contentBlockLocationCitation = citationDelta.Citation.As<ContentBlockLocationCitation>();
+    contentBlockLocationCitation!.CitedText.Should().Be("cited text");
+    contentBlockLocationCitation.DocumentIndex.Should().Be(1);
+    contentBlockLocationCitation.DocumentTitle.Should().Be("document title");
+    contentBlockLocationCitation.StartBlockIndex.Should().Be(2);
+    contentBlockLocationCitation.EndBlockIndex.Should().Be(3);
+  }
 }
\ No newline at end of file
diff --git a/tests/AnthropicClient.Tests/Unit/Models/ContentBlockLocationCitationTests.cs b/tests/AnthropicClient.Tests/Unit/Models/ContentBlockLocationCitationTests.cs
index 45fc169..8188f0c 100644
--- a/tests/AnthropicClient.Tests/Unit/Models/ContentBlockLocationCitationTests.cs
+++ b/tests/AnthropicClient.Tests/Unit/Models/ContentBlockLocationCitationTests.cs
@@ -1,7 +1,16 @@
 namespace AnthropicClient.Tests.Unit.Models;
 
-public class ContentBlockLocationCitationTests
+public class ContentBlockLocationCitationTests : SerializationTest
 {
+  private readonly string _testJson = @"{
+    ""type"": ""content_block_location"",
+    ""cited_text"": ""cited text"",
+    ""document_index"": 1,
+    ""document_title"": ""document title"",
+    ""start_block_index"": 2,
+    ""end_block_index"": 3
+  }";
+
   [Fact]
   public void Constructor_WhenCalled_ItShouldSetProperties()
   {
@@ -14,4 +23,36 @@ public class ContentBlockLocationCitationTests
     result.StartBlockIndex.Should().Be(0);
     result.EndBlockIndex.Should().Be(0);
   }
+
+  [Fact]
+  public void JsonSerialization_WhenSerialized_ItShouldHaveExpectedShape()
+  {
+    var citation = new ContentBlockLocationCitation
+    {
+      Type = "content_block_location",
+      CitedText = "cited text",
+      DocumentIndex = 1,
+      DocumentTitle = "document title",
+      StartBlockIndex = 2,
+      EndBlockIndex = 3
+    };
+
+    var result = Serialize<Citation>(citation);
+
+    JsonAssert.Equal(_testJson, result);
+  }
+
+  [Fact]
+  public void JsonDeserialization_WhenDeserialized_ItShouldHaveExpectedShape()
+  {
+    var citation = Deserialize<Citation>(_testJson);
+
+    var contentBlockLocationCitation = citation.As<ContentBlockLocationCitation>();
+    contentBlockLocationCitation!.Type.Should().Be("content_block_location");
+    contentBlockLocationCitation.CitedText.Should().Be("cited text");
+    contentBlockLocationCitation.DocumentIndex.Should().Be(1);
+    contentBlockLocationCitation.DocumentTitle.Should().Be("document title");
+    contentBlockLocationCitation.StartBlockIndex.Should().Be(2);
+    contentBlockLocationCitation.EndBlockIndex.Should().Be(3);
+  }
 }
\ No newline at end of file
diff --git a/tests/AnthropicClient.Tests/Unit/Models/DocumentContentTests.cs b/tests/AnthropicClient.Tests/Unit/Models/DocumentContentTests.cs
index 1687bdb..c5c4971 100644
--- a/tests/AnthropicClient.Tests/Unit/Models/DocumentContentTests.cs
+++ b/tests/AnthropicClient.Tests/Unit/Models/DocumentContentTests.cs
@@ -87,6 +87,16 @@ public class DocumentContentTests : SerializationTest
     action.Should().Throw<ArgumentNullException>();
   }
 
+  [Fact]
+  public void Constructor_WhenCalledWithSource_ItShouldInitializeSource()
+  {
+    var source = new DocumentSource("application/pdf", "data");
+
+    var result = new DocumentContent(source);
+
+    result.Source.Should().BeSameAs(source);
+  }
+
   [Fact]
   public void Constructor_WhenCalledWithSourceAndCacheControl_ItShouldInitializeSourceAndCacheControl()
   {
diff --git a/tests/AnthropicClient.Tests/Unit/Models/PageLocationCitationTests.cs b/tests/AnthropicClient.Tests/Unit/Models/PageLocationCitationTests.cs
index 37cc3a4..b97b629 100644
--- a/tests/AnthropicClient.Tests/Unit/Models/PageLocationCitationTests.cs
+++ b/tests/AnthropicClient.Tests/Unit/Models/PageLocationCitationTests.cs
@@ -1,7 +1,16 @@
 namespace AnthropicClient.Tests.Unit.Models;
 
-public class PageLocationCitationTests
+public class PageLocationCitationTests : SerializationTest
 {
+  private readonly string _testJson = @"{
+    ""type"": ""page_location"",
+    ""cited_text"": ""cited text"",
+    ""document_index"": 1,
+    ""document_title"": ""document title"",
+    ""start_page_number"": 2,
+    ""end_page_number"": 3
+  }";
+
   [Fact]
   public void Constructor_WhenCalled_ItShouldSetProperties()
   {
@@ -14,4 +23,36 @@ public class PageLocationCitationTests
     result.StartPageNumber.Should().Be(0);
     result.EndPageNumber.Should().Be(0);
   }
+
+  [Fact]
+  public void JsonSerialization_WhenSerialized_ItShouldHaveExpectedShape()
+  {
+    var citation = new PageLocationCitation
+    {
+      Type = "page_location",
+      CitedText = "cited text",
+      DocumentIndex = 1,
+      DocumentTitle = "document title",
+      StartPageNumber = 2,
+      EndPageNumber = 3
+    };
+
+    var result = Serialize<Citation>(citation);
+
+    JsonAssert.Equal(_testJson, result);
+  }
+
+  [Fact]
+  public void JsonDeserialization_WhenDeserialized_ItShouldHaveExpectedShape()
+  {
+    var citation = Deserialize<Citation>(_testJson);
+
+    var pageLocationCitation = citation.As<PageLocationCitation>();
+    pageLocationCitation!.Type.Should().Be("page_location");
+    pageLocationCitation.CitedText.Should().Be("cited text");
+    pageLocationCitation.DocumentIndex.Should().Be(1);
+    pageLocationCitation.DocumentTitle.Should().Be("document title");
+    pageLocationCitation.StartPageNumber.Should().Be(2);
+    pageLocationCitation.EndPageNumber.Should().Be(3);
+  }
 }
\ No newline at end of file