Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V., & Orr, R. B. (2021). Biology: A global approach (Twelfth edition, global edition.). Pearson Education Limited.

Campbell, Neil A., Lisa A. Urry, Michael L. Cain, Steven Alexander Wasserman, Peter V. Minorsky, and Rebecca B. Orr. Biology: A Global Approach. Twelfth edition, global edition. Harlow, Essex, England: Pearson Education Limited, 2021.

Campbell, Neil A., et al. Biology: A Global Approach. Twelfth edition, global edition. Pearson Education Limited, 2021.