John D. Bengtson and Merritt Ruhlen (1994) 'Global Etymologies' i On the Origin of Languages: Studies in Linguistic Taxonomy by Merritt Ruhlen. Stanford, CA: Stanford University Press, 1994. [1]Arkiverad 28 september 2007 hämtat från the Wayback Machine.
John D. Bengtson and Merritt Ruhlen (1994) 'Global Etymologies' i On the Origin of Languages: Studies in Linguistic Taxonomy by Merritt Ruhlen. Stanford, CA: Stanford University Press, 1994. [1]Arkiverad 28 september 2007 hämtat från the Wayback Machine.