Identification for ringers. 1, The genera Cettia, Locustella, Acrocephalus and Hippolais /
by Kenneth Williamson.
- 3rd rev. and enl. ed.
- [Oxford] : British Trust for Ornithology, 1968.
- 80 p., plates : ill. ; 22 cm.
- Field guide (British Trust for Ornithology) ; no.7 British Trust for Ornithology identification guide ; no. 1. .
- Field guide (British Trust for Ornithology) ; no.7 British Trust for Ornithology identification guide ; no. 1. .