1. Morphology of the F1-generation of various crosses within Rana esculenta complex;Berger;Acta Zool. Cracov.,1968
2. Systematics and hybridization in European green frogs of Rana esculenta complex;Berger;J. Herpetol.,1973
3. Hybrids of B2-generations of European water frogs (Rana esculenta complex);Berger;Ann. Zool., Warszawa,1976
4. Genetic composition and reproduction of water frog populations (Rana kl. esculenta Synklepton) near nature reserve Serrahn, GDR;Berger;Arch. Naturschutz Landsch.-forsch., Berlin,1988