ABC/Kane Productions International, Inc. ; produced in association with BBC Television ; written by Sarah Cunliffe and David R. O'Dell ; produced by Sarah Cunliffe
Encyclopaedia Britannica Educational Corporation ; a production for the Open University ; BBC ; in association with Penn State, Division of Media and Learning Resources ; produced by Rissa De La Paz
Films for the Humanities presentation ; Granada Television International ; made with the cooperation of the Wildfowl Trust, California Institute of Technology ; written by Michael Dearden and Jack Smith ; produced and directed by Jack Smith ; made in association with Norddeutscher Rundfunk