title: Commentary: classification and cluster analysis.
authors.affiliation: Institute of Psychiatry, London.
authors.forename: B S
authors.initials: BS
authors.lastname: Everitt
mesh_terms: D002965:Classification; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000209:etiology; D011247:Pregnancy; D012307:Risk Factors