Nos. 75-1372, 75-1374 to 75-1376. Argued February 10, 1976. Decided June 21, 1976. Robert A. Giannasi, Asst. Gen. Counsel, Washington, D.C., with whom John S. Irving, Jr., Gen. Counsel, Elliott Moore, Deputy Associate Gen. Counsel and Andrew F. Tranovich, Washington, D.C., were on brief for petitioner. Paul Schachter, Hato Rey, P.R., with whom David Scribner, Elizabeth Schneider, New York City, Luis M. Escribano, Hato Rey, P.R., Ralph Shapiro, New York City, and Ismael Delgado Gonzalez, San Juan