The B.T.O. Guide to Ageing & Sexing

Originally published as Part IV of 'The Bird in the Hand' byu R.K. Cornwallis & A.E. Smith (960). Second edition with revisions by Kenneth Williamson (1963) and and further revised Peter Davis (1964). 40 pp. Field Guide No. 10. 46 pp. Stiff paper wrappers.