Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) WATANABE Kinuko,De facto marriage (common-law marriage) of a person in an adoptive parent-child relationship and spousal eligibility as a recipient of a survivor's pension,社会保障研究,0387-3064,国立社会保障・人口問題研究所,2023-06,8,1,57-60,https://cir.nii.ac.jp/crid/1390297814402292480,https://doi.org/10.50870/0002000093