Feasibility assessment of double-blind, crossover, randomized controlled trial protocol comparing two oxygen-supplemented pulmonary rehabilitation for patients with chronic obstructive pulmonary disease: A pilot study - Akihiro Ito; Akane Morito; Masahiro Ishizaka; Yukihiro Ogawa; Yuki Kawai; Yuta Hanawa; Naotaka Onodera; Yoshiaki Endo; Isato Fukushi; Kotaro Takeda; Taichi Mochizuki; Yasushi Inoue; et al. (PLoS ONE, 2026)