Παραπομπή σε μορφή APA (7η εκδ.)

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.

Παραπομπή σε μορφή Chicago (17η εκδ.)

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

Παραπομπή σε μορφή MLA (9th εκδ.)

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