Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

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

Citatione MLA (9a ed.)

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