Enter works that have been written about this subject, Do not enter series of books as a single item, however -- the expected type of this property is "written work" which is an invalid type for a series. Individual components of a series should be entered instead.

Musical compositions about this subject. (Subjects are currently being refactored but there was a need to enter composition subjects before that could be completed. Hence we are using the Litarature Subject type rather than create a new type that will just have to be refactored later.)