1.  Eschmeyer, W.N., Hammann H., and Herald E.S.  1983.  Pacific Coast Fishes.  Houghton Mifflin Company.  pg.24.  P.1.
2. www.fish.../speciessummary.cfm?genusmane=Heterodontus&speciesmane=
francisci
3.  www.boatcom.com/sharks/hornshark.htm