Cita APA (7a ed.)

Williamson, E. M., By Okpako , D. T., & Evans , F. J. (1996). Pharmacological methods in phytotheropy: Research : selection, preparation and pharmacological evaluation of plant meterial. Wiley.

Cita Chicago Style (17a ed.)

Williamson, Elizabeth M., David T. By Okpako , y Fred J. Evans. Pharmacological Methods in Phytotheropy: Research : Selection, Preparation and Pharmacological Evaluation of Plant Meterial. New York: Wiley, 1996.

Cita MLA (9a ed.)

Williamson, Elizabeth M., et al. Pharmacological Methods in Phytotheropy: Research : Selection, Preparation and Pharmacological Evaluation of Plant Meterial. Wiley, 1996.