Comrie, Bernard.Haruai Numerals and their Implications for the History and Typology of Numeral Systems // Numeral Types and Changes Worldwide: Trends in Linguistics: Studies and Monographs 118 (англ.) / Gvozdanović, Jadranka. — Berlin: Morton de Gruyter, 1999. — P. 88. — ISBN 3-11-016113-3.. — «Base '20' can also be used more sporadically in a system that is basically decimal … French shows such vigesimality only in the range '80'-'99', with '80' expressed as quatre-vingts 'four-twenties', '91' as quatre-vingt-onze 'four-twenty-eleven', etc.».
