1. 1) Holt-Lunstad, J., Smith, T. B. and Layton, J. B.: Social relationships and mortality risk: A meta-analytic review, PLoS Medicine, 7(7), e1000316, 2010.7. https://doi.org/10.1371/journal.pmed.1000316
2. 2) DiJulio, B., Hamel, L., Munana, C. and Brodie, M.: Loneliness and social isolation in the United States, the United Kingdom, and Japan: An international survey, KFF Report, pp.1-29, https://www.kff.org/other/report/loneliness-and-social-isolation-in-the-united-states-the-united-kingdom-and-japan-an-international-survey/, 2018(accessed 2020.10.9).
3. 3) Cabinet Secretariat: Rules on the Establishment of the Office of Loneliness and Isolation Prevention (in Japanese), 2021.2. 内閣官房: 孤独・孤立対策担当室の設置に関する規則, https://www.cas.go.jp/jp/seisaku/kodoku_koritsu_taisaku/pdf/setti_kisoku.pdf, 2021.2(accessed 2021.7.30).
4. 4) Council for the Promotion of Measures against Loneliness and Isolation: Rules on the Establishment of the Office of Loneliness and Isolation Prevention (in Japanese). Cabinet Secretariat 2021.12 (accessed 2021.12.29) 孤独・孤立対策推進会議 : 孤独・孤立対策の重点計画,内閣官房https://www.cas.go.jp/jp/seisaku/juten_keikaku/jutenkeikaku.html, 2021.12(accessed 2021.12.29)
5. 5) Masi, C. M., Chen, H.-Y., Hawkley, L. C. and Cacioppo, J. T.: A meta-analysis of interventions to reduce loneliness. Pers. Soc. Psychol. Rev. 15, pp.219-266, 2011.8. https://doi.org/10.1177/1088868310377394