1. Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows and allies, Part I;Austin;U.S. Nat. Mus. Bull.,1968
2. The Red Crossbills of Colorado;Bailey;Publ. Denver Mus. Nat. Hist.,1953
3. Food profitability and the foraging ecology of crossbills;Benkman;Ecol. Monogr.,1987a
4. Crossbill foraging behavior, bill structure, and patterns of food profitability;Benkman;Wilson Bull.,1987b
5. Adaptations for seed dispersal and the compromises due to seed predation in limber pine;Benkman;Ecology,1984