APA

Williamson E. M., Okpako D. T. & Evans F. J. (1996). Pharmacological methods in phytotherapy research. Chichester: John Wiley & Sons.

Chicago

Williamson Elizabeth M, Okpako David T and Evans Fred J. 1996. Pharmacological methods in phytotherapy research. Chichester: John Wiley & Sons.

Harvard

Williamson E. M., Okpako D. T. and Evans F. J. (1996). Pharmacological methods in phytotherapy research. Chichester: John Wiley & Sons.

MLA

Williamson Elizabeth M, Okpako David T and Evans Fred J. Pharmacological methods in phytotherapy research. Chichester: John Wiley & Sons. 1996.