Chuen-im, Wanaphan, Saisunee Tubtimtes, and Yubol Kaewsila. 2012. “The Association Between Happiness at Workplace With Service Behaviors of Personnels at Out-Patient Units”. Ramathibodi Medical Journal 35 (4):290-99. https://he02.tci-thaijo.org/index.php/ramajournal/article/view/135464.