1. 1) Scheier D. B., J. NY State Nurses Assoc., 40, 4-10 (2009).
2. 2) Hyoguchi N., Kobayashi D., Kubota T., Shimazoe T., J. Deaf Stud. Deaf Educ., 4, 416-421 (2016).
3. 3) Ministry of Health, Labour and Welfare. The Act of Eliminating Discrimination against Persons with Disabilities: 〈https://www.mhlw.go.jp/seisakunitsuite/bunya/hukushi_kaigo/shougaishahukushi/sabetsu_kaisho/dl/iryou_guideline.pdf〉, cited 8 April, 2020.
4. 4) The Japan Research Institute, Limited. “Information barrier-free for the hearing impaired.”: 〈https://www.jri.co.jp/MediaLibrary/file/pdf/company/release/2000/0607.pdf〉, cited 8 April, 2020.
5. 5) Zennancho. “Ear Symbol.”: 〈https://www.zennancho.or.jp/mimimark/mimimark/〉, cited 8 April, 2020.