[Hart1929]
Hartman, C. G. (1929).
The breeding season of the opossum (Didelphis virginiana) and
the rate of intra-uterine and postnatal development.
J. Morph. Physiol., 46(1):143--211.
[Kooy2010]
Kooijman, S. (2010).
Dynamic Energy Budget theory for metabolic organisation.
Cambridge Univ. Press, Cambridge.
[Petr1949]
Petrides, G. A. (1949).
Sex and age determination in the opossum.
Journal of Mammalogy, 30(4):364--378.