APA-viite (7. p.)

Nagel, T. S., & Richman, P. T. (1972). Competency-based instruction: A strategy to eliminate failure; a branching programmed text. C.E. Merrill Pub.

Chicago-viite (17. p.)

Nagel, Thomas S., ja Paul T. Richman. Competency-based Instruction: A Strategy to Eliminate Failure; a Branching Programmed Text. Columbus, Ohio: C.E. Merrill Pub, 1972.

MLA-viite (9. p.)

Nagel, Thomas S., ja Paul T. Richman. Competency-based Instruction: A Strategy to Eliminate Failure; a Branching Programmed Text. C.E. Merrill Pub, 1972.