1. Embryonal and larval development of F1 generation of green frogs different combinations;Berger;Acta Zool. Crac.,1967
2. Morphology of the F1 generation of various crosses within Rana esculenta-complex;Berger;Acta Zool. Crac.,1968
3. Some characteristics of the crosses within Rana esculenta-complex in postlarval development;Berger;Ann. Zool. Warszawa,1970
4. Viability, sex and morphology of F2 generation within forms of Rana esculenta complex;Berger;Zool. Poloniae,1971
5. Systematics and hybridization in European green frogs of Rana esculenta complex;Berger;J. of Herpet.,1973