@article {1523,
	title = {Sympatry and hybridization between the clawed frogs Xenopus laevis laevis and Xenopus muelleri (Pipidae).},
	journal = {Journal of Zoology, London},
	year = {2000},
	pages = {99-107},
	author = {Fischer, W.J. and Koch, W.A. and Elepfandt, A.}
}
@article {2525,
	title = {A mitochondrial DNA perspective on the evolution of Iberian Discoglossus (Amphibia: Anura)},
	journal = {Journal of Zoology, London},
	volume = {248},
	year = {1999},
	chapter = {209},
	author = {M. Garc{\'{\i}a-Par{\'{\i}s and Jockusch, E.L.}
}
