...

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 : MediatorAwareController {

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