Engel, K.B. & Merson, R. & Hahn, M.E. & Callard, G.V. (2005)
Development of the Little Skate (Raja erinacea) as an in situ bioindicator of environmental spermatotoxicants [Abstract]. American Elasmobranch Society 21th Annual Meeting, Tampa, Florida

Engel, K.B. & Callard, G.V. (2005)
The Testis and Spermatogenesis. In W.C. Hamlett (Ed.), Reproductive biology and phylogeny of chondrichthyes: sharks, rays and chimaeras, Vol. 3 (pp. 171–200). Science Publishers, Endfield, USA