Insomnia and caregiver burden in chronic pain patients: A cross-sectional clinical study Yamaguchi, Masahiro ; Yamada, Keiko ; Iseki, Masako ; Karasawa, Yusuke ; Murakami, Yasuko ; Enomoto, Tatsuya ; Kikuchi, Nobuko ; Chiba, Satoko ; Hara, Atsuko ; Yamaguchi, Keisuke ; Inada, Eiichi Abstract Publication: PLoS ONE Pub Date: April 2020 DOI: 10.1371/journal.pone.0230933 Bibcode: 2020PLoSO..1530933Y