A Precision Amplitude-Distribution Amplifier. - William F. Caldwell; Granino A. Korn; Victor R. Latorre; Gerald R. Peterson (IRE Trans. Electron. Comput., 1960)

Biophysical information in asymmetric and symmetric Diurnal bidirectional canopy reflectance. - Vern C. Vanderbilt; Susan L. Ustin; Kevin M. Berger; William F. Caldwell; Jenny A. Clark; B. D. Gamapol; Eric S. Kasischke; Scott N. Martens; Rita E. Pettigrew; Robert A. Rousseau (IEEE Trans. Geosci. Remote. Sens., 1991)