J. R.  Houbrick, ?A survey of the littoral marine mollusks of the Caribbean coast of Costa Rica?, The Veliger, vol. 11, no. 1, pp. 4-23, 1968.

G. J.  Bakus, ?Zonation in marine gastropods of Costa Rica and species diversity?, The Veliger, vol. 10, no. 3, pp. 207-211, 1968.