著者名,書名,版表示,出版者名,出版年,シリーズ名,番号,ISBN,ISSN,URL United States. Bureau of the Census,Age at first marriage,,"U.S. Dept. of Commerce, Bureau of the Census",1973,1970 census of population,,,,https://cir.nii.ac.jp/crid/1130000796456402688