title: Understanding controlled trials. Crossover trials.
authors.affiliation: National Primary Care Research and Development Centre, University of Manchester, Manchester M13 9PL.
authors.forename: B
authors.initials: B
authors.lastname: Sibbald
authors.forename: C
authors.initials: C
authors.lastname: Roberts
mesh_terms: D018592:Cross-Over Studies; D016032:Randomized Controlled Trials as Topic / Q000379:methods*