1. Ayson, F.G., Kaneko, T., Tagawa, M., Hasegawa, S., Grau, E.G., Nishioka, R.S., King, D.K., Bern, H.A. and Hirano, T. 1993. Effects of acclimation to hypertonic environment on plasma and pituitary levels of two prolactins and growth hormone in two species of tilapia,Oreochromis mossambicus andOreochromis niloticus. Gen. Comp. Endocrinol. 89: 138–148.
2. Barlow, G.W. 1976. The Midas cichlid in Nicaragua.In Investigations of the Ichthyofauna of Nicaraguan Lakes. pp. 333–358. Edited by T.B. Thorson. University of Nebraska, Lincoln.
3. Bern, H.A. 1983. Functional evolution of prolactin and growth hormone in lower vertebrates. Am. Zool. 23: 663–671.
4. Bremer, H. 1972. Einige Untersuchungen zur Histochemie der sezernierenden Elemente der Teleostier-Epidermis. Acta Histochem. 43: 28–40.
5. Bremer, H. and Walter, U. 1986. Histologische, ultrastructurelle und topochemische Untersuchungen zur Brutpflege vonSymphysodon aequifasciatus Pellegrin 1903. Gegenbauers morph. Jahrb. Leipzig 132: 183–194.