Reference

Hans Schneider, Fawzy Hussein, Mandouh S. A. Akef (1986): Comparative bioacoustic studies in the Yellow-bellied Toad, Bombina variegata (L.), and relationships of European and Asian species and subspecies of the genus Bombina (Anura, Amphibia) – Bonn zoological Bulletin - früher Bonner Zoologische Beiträge. – 37: 49 - 67.