Lopez, D.M. & Sigel, M.M. & Lee, J.C. (1974)
Phylogenetic studies on T cells - I. Lymphocytes of the shark with differential response to phytohemagglutinin and and concanavalin A. Cellular Immunology, 10(2), 287–293
DOI: 10.1016/0008-8749(74)90120-8

Sigel, M.M. & Voss, E.W. & Rudikoff, S. (1972)
Binding properties of shark immunoglobulins. Comparative Biochemistry and Physiology – Part A, Physiology, 42(1), 249–259
DOI: 10.1016/0300-9629(72)90384-2

Sigel, M.M. & Beasley, A.R. (1967)
Biological aspects of immunization in sharks. In P.W. Gilbert, R.F. Mathewson, & D.P. Rall, (Eds.), Sharks, skates and rays. (pp. 593–610). John Hopkins Press, Baltimore