“…Twenty-eight relevant studies were identified. These included two systematic reviews (Tesarz et al, 2014; van Rood & de Roos, 2009), three randomized controlled trials (Hekmat et al, 1994; Marcus, 2008; Ray & Page, 2002), one literature review (Gerhardt et al, 2013), nine UCS (de Roos et al, 2010; Friedberg, 2004; Grant & Threlfo, 2002; Hassard, 1995; Kavakçi et al, 2012; Konuk et al 2011; Mazzola et al, 2009; Schneider et al, 2008; Wilensky, 2006), one case series (Issad et al, 2005), and 12 case studies (Amano et al, 2013; Flik & de Roos, 2010; Gauvry et al, 2013; Gorisse et al, 2010; Groet, 2012; Hughes, 2014; Kavakçi et al, 2010; Oznur & Erdem, 2013; Royle, 2008; Russell, 2008a, 2008b; Silver et al, 2008).…”