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SOURCES: Campbell & de Waal (2011); Campbell & others (2009); Cartwright (2004); Empson (2002); Joly-Mascheroni & others (2008); Landolt (2008); Platek & others (2005); Pressman (2007); Rétey & others (2005); Romero & others, 2013; Takeuchi & others (2002).