R. E.  Walker, ?Investigation in vegetation map rectification, and the remotely sensed detection and measurement of natural vegetation changes?, 2000.

F. W.  Davis, Stoms, D. M., Hollander, A. D., Thomas, K. A., Stine, P. A., Odion, D., Borchert, M. I., Thorne, J. H., Gray, M. V., Walker, R. E., Warner, K., and Graae, J., ?The California Gap Analysis Project-Final Report?. University of California, Santa Barbara, 1998.

F. W.  Davis and Walker, R. E., ?Investigations into the use of airborne multispectral images for estimating conifer mortality in Sierran montane forests?, University of California, Santa Barbara, 1993.

F. W.  Davis and Walker, R. E., ?Investigations into the use of airborne multispectral images for estimating conifer mortality in Sierran montane forests?. University of California, Santa Barbara, 1993.

R. E.  Walker, Stoms, D. M., Davis, F. W., and van Wagtendonk, J., ?Modeling vegetation cover types from a topographic gradient in the southern Sierra Nevada?, in Gis/lis'92, San Jose, 1992, pp. 794-803.

R. E.  Walker, Stoms, D. M., Estes, J. E., and Cayocca, K. D., ?Relationships between biological diversity and multitemporal vegetation index data in California?, in 1992 Annual Meeting of ASPRS/ACSM, Albuquerque, 1992, pp. 562-571.