Signals for survival /
Tinbergen, Niko,1907-1988.
Falkus, Hugh.
Ennion, E. A. R.(Eric Arnold Roberts),-1981.
Oxford Clarendon P
1970
'This book is based on the film "Signals for Survival" by Niko Tinbergen and Hugh Falkus, commissioned by the British Broadcasting Corporation' ... - note
bibl p80
Animal communication.
Lesser black-backed gull.