APA (7th ed.) Citation

Marshall, A., & Guillebaud, C. W. (1961). Principles of economics (9th (variorum) ed.). MacMillan for The Royal Economic Society.

Chicago Style (17th ed.) Citation

Marshall, Alfred, and C. W. Guillebaud. Principles of Economics. 9th (variorum) ed. London [etc.]: MacMillan for The Royal Economic Society, 1961.

MLA (9th ed.) Citation

Marshall, Alfred, and C. W. Guillebaud. Principles of Economics. 9th (variorum) ed. MacMillan for The Royal Economic Society, 1961.

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