Takashi Omoto, Junichi Asaka, Takamasa Sakai, Fumihiko Sato, Nobuyuki Goto, Kenzo Kudo: Disproportionality analysis of safety signals for a wide variety of opioid-related adverse events in elderly patients using the Japanese Adverse Drug Event Report (JADER) database. Biological & Pharmaceutical Bulletin, 44(5):627-634, 2021