APA (7th ed.) Citation

Gordon, R., & Power, A. J. (1993). Enrichment through variation.

Chicago Style (17th ed.) Citation

Gordon, Robert, and Anthony John Power. Enrichment Through Variation. Edinburgh, 1993.

MLA (9th ed.) Citation

Gordon, Robert, and Anthony John Power. Enrichment Through Variation. 1993.

Warning: These citations may not always be 100% accurate.