Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) NISHIOKA Chifumi and SATO Sho,The State of Open Access in Japan: An Analysis Using Unpaywall,Joho Chishiki Gakkaishi,0917-1436,Japan Society of Information and Knowledge,2021-02-28,31,1,31-50,https://cir.nii.ac.jp/crid/1390850424378706816,https://doi.org/10.2964/jsik_2021_016