Percy, K. A.; Psacharopoulos, George; Olsen, Johan P.; Vaughan, Michalina; Purdy, Leslie; Mukherjee, K. C.; Streit, Max; Hounsell, D. J.; Peterson, Marvin W.
(Kluwer Academic Publishers; Elsevier Scientific Publishing Company ; Springer Science+Business Media, 1974-11)