Gropper, G. L., & Glasgow, Z. (1971). Criteria for the selection and use of visuals in instruction: A handbook. Educational Technology.
Chicago (17e ed.) BronvermeldingGropper, George L., en Zita Glasgow. Criteria for the Selection and Use of Visuals in Instruction: A Handbook. Englewood Cliffs, NJ: Educational Technology, 1971.
MLA (9e ed.) BronvermeldingGropper, George L., en Zita Glasgow. Criteria for the Selection and Use of Visuals in Instruction: A Handbook. Educational Technology, 1971.
Let op: Deze citaties zijn niet altijd 100% accuraat.