APA (7th ed.) Citation

Clapham, A. R., Tutin, T. G., & Warburg, E. F. (1968). Excursion flora of the British Isles (2nd ed.). Cambridge University Press.

Chicago Style (17th ed.) Citation

Clapham, A. R., T. G. Tutin, and E. F. Warburg. Excursion Flora of the British Isles. 2nd ed. Cambridge: Cambridge University Press, 1968.

MLA (9th ed.) Citation

Clapham, A. R., et al. Excursion Flora of the British Isles. 2nd ed. Cambridge University Press, 1968.