Schulze, Wolfgang (2007). "Haspelmath, Martin & Matthew S. Dryer & Davil Gil & Bernard Comrie. 2005.The World Atlas of Language Structures". Studies in Language. 31 (2): 445–463. doi:10.1075/sl.31.2.08sch. ISSN0378-4177.
Schulze, Wolfgang (2007). "Haspelmath, Martin & Matthew S. Dryer & Davil Gil & Bernard Comrie. 2005.The World Atlas of Language Structures". Studies in Language. 31 (2): 445–463. doi:10.1075/sl.31.2.08sch. ISSN0378-4177.