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

@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{FrosBall1979,
 doi = {10.1080/00306525.1979.9634117},
 author = {P. G. H. Frost and I. J. Ball and W. R. Siegfried and F. McKinney},
 year = {1979},
 title = {SEX RATIOS, MORPHOLOGY AND GROWTH OF THE {A}FRICAN BUCK DUCK},
 journal = {Ostrich},
 volume = {50},
 pages = {220--233}
} 

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

@Article{PrinPres1991,
 doi = {10.1016/0300-9629(91)90122-S},
 author = {R. Prinzinger and A.Pre{\ss}mar and E. Schleucher},
 year = {1991},
 title = {Body temperature in birds},
 journal = {Comp. Biochem. Physiol.},
 volume = {99A(4)},
 pages = {499-506}
}