title: The crown-rump length in early human pregnancy: a reappraisal.
authors.forename: M S
authors.initials: MS
authors.lastname: Mills
mesh_terms: D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011272:Pregnancy, Multiple