1. WALDMAN, R.K., LEIBEN, J., and KRAUSE, L., A.M.A. Arch. Ind. Hyg. Occupational Med. 9, 37 (1954).
2. ELLIOTT, J.W., WALKER, K.C., PENICK, A.E., and DURHAM, W.F., J. Agr. Food Chem. 8, 111 (1960).
3. ATTERBERRY, J.D., DURHAM, W.F., ELLIOTT, J.W., and WOLFE, H.R., Arch. Environ. Health 3, 376 (1961).
4. ESPOSITO, G.G., Anal. Chem. 40, 1902 (1968).