title: Crossover designs versus parallel studies in infertility research.
authors.forename: E R
authors.initials: ER
authors.lastname: te Velde
authors.forename: B J
authors.initials: BJ
authors.lastname: Cohlen
authors.forename: C W
authors.initials: CW
authors.lastname: Looman
authors.forename: J D
authors.initials: JD
authors.lastname: Habbema
mesh_terms: D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D012107:Research Design