“Are pension types associated with happiness in Japanese older people?: JAGES cross-sectional study,” by Ichiro Sasaki, Katsunori Kondo, Naoki Kondo, Jun Aida, Hiroshi Ichikawa, Takashi Kusumi, Naoya Sueishi, and Yuichi Imanaka (PLoS ONE 13(5): e0197423. doi.org/10.1371/journal.pone.0197423, XML, HTML, and .pdf format, 14p.).
journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0197423