Estrada, J.A. & Rice, A.N. & Natanson, L.J. & Skomal, G.B. (2006)
Use of isotopic analysis of vertebrae in reconstructing ontogenetic feeding ecology in white sharks. Ecology, 87(4), 829–834
DOI: 10.2307/20069012

Estrada, J.A. & Rice, A.N. & Lutcavage, M.E. & Skomall, G.B. (2003)
Predicting trophic position in sharks of the north-west Atlantic Ocean using stable isotope analysis. Journal of the Marine Biological Association of the United Kingdom, 83(6), 1347–1350
DOI: 10.1017/s0025315403008798