When should placebo surgery as a control in clinical trials be carried out? द्वारा George, A, Collett, C, Carr, A, Holm, S, Bale, C, Burton, S, Campbell, M, Coles, A, Gottlieb, G, Muir, K, Parroy, S, Price, J, Rice, A, Sinden, J, Stephenson, C, Wartolowska, K, Whittall, H