1. Austin CR, Short RV (eds) (1984) Reproduction in mammals, vol 3. Hormonal control of reproduction, 2nd edn. Cambridge University Press, Cambridge
2. Bentley PJ (1982) Comparative vertebrate endocrinology, 2nd edn. Cambridge University Press, Cambridge
3. Cowie AT, Forsyth IA, Hart IC (1980) Hormonal control of lactation. Springer, Berlin Heidel-berg New York
4. Ensor DM (1978) Comparative endocrinology of prolactin. Chapman and Hall, London
5. Griffith M (1978) The biologiy of the Monotremes. Academic Press, New York