author = { Katzer, Bernd },

title = { Hohe Jungenzahl beim Höckerschwan Cygnus olor = Large numbers of Mute Swan Cygnus olor joung birds offspring },

publisher = {},

isbn = {0942-7872},

keywords = { Zehren-Wölkisch , Höckerschwan , Brutbiologie },

year = {2020},

abstract = {Literaturangaben},

address = { },

url = { http://slubdd.de/katalog?TN_libero_mab2 }