APA (7th ed.) Citation

Clark, H. M., Clark, T. M., & Harmer, G. R. (1947). Scott's standard postage stamp catalogue: The Encyclopedia of Philately. Scott Publications.

Chicago Style (17th ed.) Citation

Clark, Hugh M., Theresa M. Clark, and Gordon R. Harmer. Scott's Standard Postage Stamp Catalogue: The Encyclopedia of Philately. Nueva York: Scott Publications, 1947.

MLA (9th ed.) Citation

Clark, Hugh M., et al. Scott's Standard Postage Stamp Catalogue: The Encyclopedia of Philately. Scott Publications, 1947.