Cita APA (7th ed.)

Powell, L. S. (1973). A guide to the use of visual aids (3rd ed. rev.). British Assoc. for Commercial and Industrial Education.

Cita Chicago (17th ed.)

Powell, Leonard Sutherland. A Guide to the Use of Visual Aids. 3rd ed. rev. Lond.: British Assoc. for Commercial and Industrial Education, 1973.

Cita MLA (8th ed.)

Powell, Leonard Sutherland. A Guide to the Use of Visual Aids. 3rd ed. rev. British Assoc. for Commercial and Industrial Education, 1973.