Sherman, J. Gilmour 1931- The personalized system of instruction / J. Gilmour Sherman and Robert S. Ruskin. - Englewood Cliffs, N.J. : Educational Technology Publications, c1999. - xi, 114 p. ; 24 cm. - The Instructional design library ; v. 13 . Bibliography: p. 51-53. ISBN: 0877781176 LCCN: 77025415 Subjects--Topical Terms: Independent study. LC Class. No.: LB1049 / .S485 Dewey Class. No.: 378.1/7/943