HELLEBREKERS WPJ (1961) Oölogische nidologische and communications, 1959-II and 1960. Dimensions and weights of a clutch of the Mute Swan Cygnus olor of the Zwarte Meer. LIMOSA 34 (3): 265-265.
Dimensions and weights of a clutch of the Mute Swan Cygnus olor of the Zwarte Meer
