Amphibians : The World of Frogs, Toads, Salamanders and Newts
by Robert Hofrichter, Friefly Books, 2000
ISBN # 155209541X

Encyclopedia of Reptiles & Amphibians
by Harold G. Cogger, Richard G. Zweifel and DavidKirshner, Raintree / Steck Vaughn, 1999
ISBN # 0739806858X

Amphibians in Danger : A worldwide Warning !
by Ron Frideu, Franklin Watts Inc., 1999
ISBN # 0531117375

California Zoological Supply :
 http://www.calzoo.com/html/tomatofrogs.html

 All About Frogs :
 http://allaboutfrogs.org

Sedgwick County Zoo :
 http://www.scz.org/animals/f/tomato.html