1. East African bird ringing report 1969-70;Backhurst;Jl E. Afr. nat. Hist. Soc.,1971
2. Internal timer of spring migration in an equatorial migrant, the Yellow Wagtail Motacilla flava;Curry-Lindahl;Ark. Zool.,1958
3. Migration seasons of the Sylvia warblers at British bird observatories;Davis;Bird Study,1967
4. Dementiev , G. P. et al. 195154 Birds of the Soviet Union