because I can not add the visual reference compilerservices?

I need to use this library for my program but it does not appear anywhere. The library is

visual compilerservices

The errors I get are.

  

The name 'CallType' does not exist in the current context (CS0103) -   C: \ Users \ Silvul \ Documents \ SharpDevelop Projects \ Wero \ MyClass.cs: 34,549   The name 'Versioned' does not exist in the current context (CS0103) -   C: \ Users \ Silvul \ Documents \ SharpDevelop Projects \ Wero \ MyClass.cs: 34,61   The name 'CallType' does not exist in the current context (CS0103) -   C: \ Users \ Silvul \ Documents \ SharpDevelop Projects \ Wero \ MyClass.cs: 35,299   The name 'Versioned' does not exist in the current context (CS0103) -   C: \ Users \ Silvul \ Documents \ SharpDevelop Projects \ Wero \ MyClass.cs: 35,61