A Pilot Randomised, Open, Uncontrolled, Clinical Study of Two Dosages of St John’s Wort (Hypericum perforatum) Herb Extract (LI-160) as an Aid to Motivational/Behavioural Support in Smoking Cessation - Barnes, Joanne; Barber, Nick; Wheatley, David; Williamson, Elizabeth M (Planta Medica, 2006)