Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Nicole K. Valtorta and Danielle Collingridge Moore and Lynn Barron and Daniel Stow and Barbara Hanratty,Older Adults’ Social Relationships and Health Care Utilization: A Systematic Review,American Journal of Public Health,0090-0036,American Public Health Association,2018-04,108,4,e1-e10,https://cir.nii.ac.jp/crid/1363670319380196992,https://doi.org/10.2105/ajph.2017.304256