Mavenlink External References API
External References allows users see which objects (one of `Assignment`, `BillingMilestone`, `CustomField`, `CustomFieldChoice`, `CustomFieldSet`, `CustomFieldValue`, `Estimate`, `EstimateScenario`, `EstimateScenarioResource`, `Expense`, `ExpenseBudget`, `Invoice`, `Participation`, `Post`, `RateCard`, `Role`, `Skill`, `StatusReport`, `Story`, `StoryAllocationDay`, `Submission`, `SurveyAnswer`, `SurveyQuestion`, `SurveyResponse`, `SurveyTemplate`, `TimeEntry`, `TimeOffEntry`, `User`, `Vendor`, `Workspace`, `WorkspaceAllocation`, `WorkspaceGroup`, or `WorkspaceResource` are synced with third party systems. This allows you to view the sync status of items in addition to the integration specifics for a synced object. Objects that are synced with a third party system have external integration attributes that include the corresponding ID of the third-party object with which it is synced, a link that allows you to view the object in the third party system, the status of the external object in the external system, the status of the sync, and a link to exceptions.