Willamson, Elizabeth M. Selection, preparation and pharmacological evaluation of plant material Pharmacological methods in phytotherapy research volume 1 Elizabeth M. Williamson, David T. Okpako, Fred J. evans - England John Wiley & Sons 1996 - ix, 228 p. ISBN: 0471942170 Subjects--Topical Terms: Pharmacognosy LC Class. No.: RS164 / .W55 1996 v. 1 c. 1