Contributors: Encyclopaedia Britannica, Inc., publisher., Rafferty, John P., narrator., Heintz, Kurt, director.

Availability: https://www.aspresolver.com/aspresolver.asp?MARC;5136734

Contributors: BBC Scotland, production company., Science Channel (Television network), production company., Budd, Nathan, producer.

Availability: https://www.aspresolver.com/aspresolver.asp?MARC;4037796

Contributors: Visual Learning Systems, production company., Jerome, Brian A., producer., Keck, Nina, narrator.

Availability: https://www.aspresolver.com/aspresolver.asp?MARC;3404137