LITERATURE CITED
Achilles, Laurence.
1906. Nesting of the Arctic three-toed woodpecker in the Adirondacks. Bird-Lore, vol. 8, pp. 158-160.
Agersborg, Gilbert Smith.
1881. Novel nesting-sites of woodpeckers (Colaptes auratus and Melanerpes erythrocephalus). Bull. Nuttall Orn. Club, vol. 6, p. 120.
Alderson, V. A.
1890. Hairy woodpecker and potato bugs. Oologist, vol. 7, p. 147.
Allen, Arthur Augustus.
1928. Downy woodpecker’s story. Bird-Lore, vol. 30, pp. 415-424.
1937. Hunting with a microphone the voices of vanishing birds. Nat. Geogr. Mag., vol. 71, pp. 697-706.