title: Endovaginal US: cardiac activity in embryos of less than 5.0 mm in crown-rump length.
authors.forename: F N
authors.initials: FN
authors.lastname: Tessler
mesh_terms: D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D006801:Humans; D011247:Pregnancy; D016216:Ultrasonography, Prenatal