1. Biometrical studies on the populations of green frogs from the environs of Poznan;Berger;Ann. Zool.,1966
2. An all-hybrid water frog population persisting in agrocenoses of central Poland (Amphibia, Salientia. Ranidae);Berger;Proc. Acad. Nat. Sci. Philadelphia,1988a
3. On the origin of genetic systems in European water frog hybrids;Berger;Zool. Poloniae,1988b
4. Progeny of water frog populations in central Poland;Berger;Amphibia-Reptilia,1992
5. Persistance of all-hybrid water frog populations (Rana kl. esculenta) in northern Germany;Berger;Gen. Pol.,1994