著者名,論文名,雑誌名,ISSN,出版者名,出版日付,巻,号,ページ,URL,URL(DOI) BARBARA SH,Diagnosis of placenta previa during the third trimester. Role of Transperineal sonography,Am J Radiol,,,1992,83,,159-162,https://cir.nii.ac.jp/crid/1574231875191909120,