title: How homogeneous are comparison groups in any study evaluating techniques of embryo transfer?
authors.forename: Gerard S
authors.initials: GS
authors.lastname: Letterie
authors.forename: Linda O
authors.initials: LO
authors.lastname: Eckert
mesh_terms: D004624:Embryo Transfer / Q000592:standards*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans