References

1 Fred S. Keller. Goodbye, teacher ... J. of Applied Behavioral Analysis, 1(1):79-89, Spring 1968.

2 J. Gilmour Sherman and Robert S. Ruskin. The Personalized System of Instruction. Educational Technology Publications, Englewood Cliffs, NJ, 1978. Vol. 13 in The Instructional Design Library, series ed. Danny G. Langdon.

3 J. Gilmour Sherman, Robert S. Ruskin, and George B. Semb, editors. The Personalized System of Instruction: 48 seminal papers. TRI Publications, Lawrence, Kansas, 1982.