"The John W. Campbell Memorial Award". Center for the Study of Science Fiction, Department of English, University of Kansas. Archived from the original on 5 February 2012. Retrieved 28 November 2010.
"1981 Hugo Awards". World Science Fiction Society. Archived from the original on 7 May 2011. Retrieved 28 November 2010.
"The John W. Campbell Memorial Award". Center for the Study of Science Fiction, Department of English, University of Kansas. Archived from the original on 5 February 2012. Retrieved 28 November 2010.