^M.L. Crump (1996). Parental care among the AmphibiaISBN 9780120045259 (revised May 2012)
^M.L. Crump (1996). Parental care among the AmphibiaISBN 9780120045259 (revised May 2012)
^Advances in the Study of Behavior Vol. 25 : Parental Care: Evolution, Mechanisms, and Adaptive Significance (1996, Hardcover)ISBN 9780120045259 (revised Feb 2017)