Rob Hume, Robert Still, Andy Swash and Hugh Harrop, consultant: Chris Batty, photgraphic associate: Agami Photo AgencyPrinceton University Press2021<RA6-D2>
Erik Hirschfeld, Andy Swash & Robert Still, with contributions by Nick Langley [and three others], and illustrations by Tomasz Cofta.Princeton University Press[2013]<RA567-B78>
by Jean Craighead George ; illustrations by Betty Fraser ; produced by the Division of Publications, National Park ServiceU.S. Dept. of the Interior1988