Concise encyclopedia of languages of the worldArchived 2011-12-26 at the वेबैक मशीन, Keith Brown, Sarah Ogilvie, Elsevier, 2008, ISBN 978-0-08-087774-7, ... The most serious problems are the extensive borrowing among the 'Altaic' languages, lack of convincing cognates, lack of basic vocabulary, extensive areal diffusion, problems with the putative sound correspondences ...
Concise encyclopedia of languages of the worldArchived 2011-12-26 at the वेबैक मशीन, Keith Brown, Sarah Ogilvie, Elsevier, 2008, ISBN 978-0-08-087774-7, ... The most serious problems are the extensive borrowing among the 'Altaic' languages, lack of convincing cognates, lack of basic vocabulary, extensive areal diffusion, problems with the putative sound correspondences ...