Microform. Washington, D.C., U.S. G.P.O., 1983. 6 microfiche : negative. Photocopy. Springfield, VA : U.S. Dept. of Commerce, National Technical Information Service, 1984. 28 cm. PB84-128667. Microfiche. [Washington, D.C.] : U.S. G.P.O., [1983]. 6 microfiches ; 11 x 15 cm.