by F. Hercik and H. Jammet. by S. Wernick and R. Pinner. by J. Fouchier and F. Billet. by L. Lov鈇sz and M.D. Plummer. by R. Belcher and A. L. Godbert. by W.F. Markwick and W.A. Smith. by H.H. Rosenbrock and C. Storey.