The family has hardly been studied by linguists (as of Adelaar & Muysken 2004), although several studies have recently appeared (see: Bertinetto 2009, 2010, 2013; Ciucci 2007/08, 2009, 2010a, 2010b, 2013a, 2013b).
Linguists have only minimally investigated the family (as per Adelaar & Muysken 2004), although recent studies have emerged (see: Bertinetto 2009, 2010, 2013; Ciucci 2007/08, 2009, 2010a, 2010b, 2013a, 2013b).