Espich, J. E., & Williams, B. (1967). Developing programmed instructional materials: A handbook for program writers. Lear Siegler.
Citazione stile Chigago Style (17a edizione)Espich, James E., e Bill Williams. Developing Programmed Instructional Materials: A Handbook for Program Writers. s.l: Lear Siegler, 1967.
Citatione MLA (9a ed.)Espich, James E., e Bill Williams. Developing Programmed Instructional Materials: A Handbook for Program Writers. Lear Siegler, 1967.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.