APA (7th ed.) Citation

Heywood, V. H. (1993). Flowering plants of the world (Updated ed.). Oxford University Press.

Chicago Style (17th ed.) Citation

Heywood, V. H. Flowering Plants of the World. Updated ed. New York: Oxford University Press, 1993.

MLA (9th ed.) Citation

Heywood, V. H. Flowering Plants of the World. Updated ed. Oxford University Press, 1993.