produced by Steven Latham, Larry Klein, Evan I. Schwartz ; written by Larry Klein and Evan I. Schwartz ; directed by Steven Latham ; a Steven Latham production for WGBH/NOVA
produced and directed by Patsy Northcutt, David Kennard ; written by Brian Thomas Swimme, Mary Evelyn Tucker ; Yale School of Forestry & Environmental Studies ; Northcutt Productions
Bullfrog Films presents ; directed by David Springbett ; producers, David Springbett, Heather MacAndrew ; writer, Heather MacAndrew ; produced by Asterisk Productions ; produced in association with the Canadian Broadcasting Corporation
a report by Andreas Ewels ; written and directed by Andreas Ewels ; director, Norbert Porta ; production, Alexandre Kegler, Sigrid Beck ; produced by Sciencedocu on behalf of ZDF