by Sprague J.W
Published in Plant patent - United States Patent and Trademark Office (USA). no. 7337 (1990)

by Brown, D.M., Cady, W.R., Sprague, J.W., Salvagni, P.J.
Published in IEEE transactions on electron devices (01.10.1971)

by Sprague, J.W
Published in United States patent. Plant - United States Patent and Trademark Office (USA) (01.03.1988)

by Pevear D.R, Goldin A, Sprague J.W
Published in Soil Science Society of America journal (1984)

by Rosen, A., Stabile, P., Janton, W., McShea, J.C., Rosenberg, A., Petheram, J.C., Miller, H.G., Sprague, J.W., Gilman, J.M.
Published in IEEE photonics technology letters (01.02.1989)

by Pevear D.R, Goldin A, Sprague J.W
Published in Soil Science Society of America journal (01.01.1984)