when André-Georges Haudricourt demonstrated that the tones of Vietnamese were reflexes of final consonants from Proto-Mon–Khmer. Many Chinese linguists continue to follow Li's classification. However, this arrangement remains problematic. For example, there is disagreement over whether to include the entire Kra–Dai family or just Kam–Tai (Zhuang–Dong excludes the Kra languages), because the Chinese cognates that form the basis of the putative relationship are not found in all branches of the family and have not been reconstructed for the family as a whole. In addition, Kam–Tai itself no longer appears to be a valid node within Kra–Dai. Benedict (1942) Benedict overtly excluded Vietnamese (placing it in Mon–Khmer) as well as Hmong–Mien and Kra–Dai (placing them in Austro-Tai). He otherwise retained the outlines of Conrady's Indo-Chinese classification, though putting Karen in an intermediate position: Sino-Tibetan Chinese Tibeto-Karen Karen Tibeto-Burman Shafer (1955) Shafer criticized the division of the family into Tibeto-Burman and Sino-Daic branches, which he attributed to the different groups of languages studied by Konow and other scholars in British India on the one hand and by Henri Maspero and other French linguists on the other. He proposed a detailed classification, with six top-level divisions: Sino-Tibetan Sinitic Daic Bodic Burmic Baric Karenic Shafer was sceptical of the inclusion of Daic, but after meeting Maspero in Paris decided to retain it pending a definitive resolution of the question. Matisoff (1978, 2015) James Matisoff abandoned Benedict's Tibeto-Karen hypothesis: Sino-Tibetan Chinese Tibeto-Burman Some more-recent Western scholars, such as Bradley (1997) and La Polla (2003), have retained Matisoff's two primary branches, though differing in the details of Tibeto-Burman. However, Jacques (2006) notes, "comparative work has never been able to put forth evidence for common innovations to all the Tibeto-Burman languages (the Sino-Tibetan languages to the exclusion of Chinese)" and that "it no longer seems justified to treat Chinese as the first branching of the Sino-Tibetan family," because the morphological divide between Chinese and Tibeto-Burman has been bridged by recent reconstructions of Old Chinese. The internal structure of Sino-Tibetan has been tentatively revised as the following Stammbaum by Matisoff in the final print release of the Sino-Tibetan Etymological Dictionary and Thesaurus (STEDT) in 2015. Matisoff acknowledges that the position of Chinese within the family remains an open question. Sino-Tibetan Chinese Tibeto-Burman Northeast Indian areal group "North Assam" Tani Deng Kuki-Chin "Naga" areal group Central Naga (Ao group) Angami–Pochuri group Zeme group Tangkhulic Meitei Mikir / Karbi Mru