Callender, P. (1969). Programmed Learning: Its development and structure. Longmans.
Cita Chicago (17th ed.)Callender, Patricia. Programmed Learning: Its Development and Structure. London: Longmans, 1969.
Cita MLA (9th ed.)Callender, Patricia. Programmed Learning: Its Development and Structure. Longmans, 1969.
Atenció: Aquestes cites poden no estar 100% correctes.