diff --git a/README.md b/README.md
index 18f6a07..8aae835 100644
--- a/README.md
+++ b/README.md
@@ -18,3 +18,18 @@ result.IsSuccess
 result.Result
 ```
 
+### IRetryIntervalStrategy
+
+```csharp
+var builder = RetryBuilder.Default.ConfigureOptions(options =>
+{
+    options.RetryInterval = new ConstantRetryInterval(TimeSpan.FromMilliseconds(100));
+});
+
+var builder = RetryBuilder.Default.ConfigureOptions(options =>
+{
+    options.RetryInterval =
+        new ExponentialRetryInterval(TimeSpan.FromMilliseconds(100), TimeSpan.FromSeconds(60));
+}); 
+```
+
diff --git a/src/RetryCore/RetryCore.csproj b/src/RetryCore/RetryCore.csproj
index 3e8dabc..9da0e58 100644
--- a/src/RetryCore/RetryCore.csproj
+++ b/src/RetryCore/RetryCore.csproj
@@ -8,7 +8,7 @@
 		<GenerateDocumentationFile>True</GenerateDocumentationFile>
 		<LangVersion>latest</LangVersion>
 
-    <Version>0.2.0</Version>
+    <Version>0.3.0</Version>
     <PackageId>$(AssemblyName)</PackageId>
     <Description>A library for retrying operations.</Description>
     <Authors>jerviscui</Authors>