“…Search strings were adapted according to the database (see Appendix A). The reference lists of three meta-analyses (Bolier et al, 2013;Chakhssi, Kraiss, Sommers-Spijkerman, & Bohlmeijer, 2018;Dickens, 2017) and seven review articles on PPIs (Casellas-Grau, Font, & Vives, 2014;Ghosh & Deb, 2016;Macaskill, 2016;Rashid, 2015;Sutipan, Intarakamhang, & Macaskill, 2017;Walsh, Cassidy, & Priebe, 2016;Woodworth, O-Brien-Malone, Diamond, & Schüz, 2016) were also checked. In addition, a hand search through the websites of three known non-Western journals in the field of positive psychology was conducted, namely, the websites of the Indian Journal of Positive Psychology, the Iranian Journal of Positive Psychology, and the Middle East Journal of Positive Psychology.…”