1. The Relationship of Secondary Cavity Nesters to Snag Densities in Western Coniferous Forests. Forest Wildlife Habitat Technical Bulletin 1;Balda,1975
2. Emerging concepts and research directions in the study of cavity-nesting birds: keystone ecological processes;Bednarz;Condor,2004
3. Bevis, K., Martin, S., 2002. Habitat preferences of primary cavity excavators in Washington's East Cascades. In: Laudenslayer, Jr., W., Shea, P., Valentine, B., Weatherspoon, C., Lisle, T. (Technical coordinators), Proceedings of the Symposium on the Ecology and Management of Coarse Woody Debris in Western Forests. USDA Forest Service General Technical Report, PSW-GTR-181, pp. 207–221.
4. Effects of urban sprawl on snags and the abundance and productivity of cavity-nesting birds;Blewett;Condor,2005
5. Breeding bird populations of burned and unburned conifer forest in the Sierra Nevada;Bock;Condor,1970