1920. A colony of three-toed woodpeckers. Bird-Lore, vol. 22, pp. 351-352.

Willard, Francis Cottle.

1912. A week afield in southern Arizona. Condor, vol. 14, pp. 53-63.

1918. Evidence that many birds remain mated for life. Condor, vol. 20, pp. 167-170.

Wilson, Alexander.

1832. American ornithology, vol. 1. (1811 edition also cited.)

Wood, John Claire.

1905. Some nesting sites of the hairy woodpecker (Dryobates villosus). Wilson Bull., vol. 17, p. 66.

Woods, Robert S.

1932. Acquired food habits of some native birds. Condor, vol. 34, pp. 237-240.