@techreport{oai:sapmed.repo.nii.ac.jp:00018335,
 author = {宮嶋, 俊一},
 month = {Mar},
 title = {Spread of COVID-19 and Elderly People Living Alone in Hokkaido【ＳＨＯＲＴ ＣＯＭＭＵＮＩＣＡＴＩＯＮ】},
 year = {2023}
}