@Misc{Wiki,
 howpublished = {\url{http://en.wikipedia.org/wiki/Didelphis_virginiana}}
} 

@Book{Kooy2010,
 author = {Kooijman, S.A.L.M.},
 year = {2010},
 title  = {Dynamic Energy Budget theory for metabolic organisation},
 publisher = {Cambridge Univ. Press, Cambridge},
 pages = {Table 4.2 (page 150), 8.1 (page 300)},
 howpublished = {\url{../../../bib/Kooy2010.html}}
} 

@Article{Hart1929,
 author = {Hartman, C. G.},
 year = {1929},
 title = {The breeding season of the opossum (\emph{Didelphis virginiana}) and the rate of intra-uterine and postnatal development},
 journal = {J. Morph. Physiol.},
 volume = {46},
 number = {1},
 pages = {143--211}
} 

@Article{Petr1949,
 author = {George A. Petrides},
 year = {1949},
 title = {Sex and Age Determination in the Opossum},
 journal = {Journal of Mammalogy},
 volume = {30},
 number = {4},
 pages = {364-378}
} 

@Misc{AnAge,
 howpublished = {\url{http://genomics.senescence.info/species/entry.php?species=Didelphis_virginiana}}
}