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

@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{Schl1998,
 author = {Schlee, M. A.},
 year = {1998},
 title = {Hand-rearing R\"{u}ppell's griffon vulture \emph{Gyps ruepellii} at {Paris Menagerie, Milwaukee County zoo and Burger's Zoo, Arnhem}},
 journal = {Int. Zoo Yb.},
 volume = {36},
 pages = {179--194}
} 

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

@Misc{bow,
 howpublished = {\url{https://birdsoftheworld.org/bow/species/eurgri1/cur/introduction}}
} 

@Misc{avibase,
 howpublished = {\url{https://avibase.bsc-eoc.org/species.jsp?lang=EN&avibaseid=5D1987CEE4005AA2&sec=lifehistory}}
}