Wang, F. (2006). HISTORICAL STRATIFICATION IN LINGUISTICS. Journal of Chinese Linguistics, 34(2), 169-171. https://www.airitilibrary.com/Article/Detail?DocID=P20181204001-200606-201812140011-201812140011-169-171
Szeto, L. Y. (2001). Between dialect and language [master's thesis, The University of Hong Kong]. Airiti Library. https://www.airitilibrary.com/Article/Detail?DocID=U0029-1812201200006009