1. Nocturnal bird migrants:two methods of flight orientation?;Able;Bull. ecol. Soc. Am.,1970a
2. A radar study of the altitude of nocturnal passerine migration;Able;Bird-Banding,1970b
3. Radar observations of bird migration in Cyprus;Adams;Bird-Banding,1962
4. Barometric pressure-patterns and spring bird migration;Bagg;Wilson Bull.,1950