...

namespace MDM.Api.Features.V1.Sources {

   // Will be supported from version "1.0" onwards
   [ApiVersions("1.0")]
   [RoutePrefix("v{version:apiVersion}/sources")]
   public class SourcesController : ApiController {

      // We override the default controller versioning for this specific endpoint.
      // Will be supported from version "1.0" until version "2.0", inclusive.
      // The last parameter marks the endpoint as deprecated.
      [ApiVersion("1.0", "2.0", true)]
      [HttpGet]
      public async Task<IHttpActionResult> Get() {
          ...
      }
   }
}

namespace MDM.Api.Features.V3.Sources {

   // Will be supported from version "3.0" onwards
   [ApiVersions("3.0")]
   [RoutePrefix("v{version:apiVersion}/sources")]
   public class SourcesController : ApiController {

      [HttpGet]
      public async Task<IHttpActionResult> Get() {
          ...
      }
   }
}