In 1970 a supplement to this article was published. The supplement can be accessed at commons.und.edu/sil-work-papers/vol14/iss1/8/
Kosin, Wesley L.
Work Papers of the Summer Institute of Linguistics, University of North Dakota Session: Vol. 11, Article 4.
Available at: https://commons.und.edu/sil-work-papers/vol11/iss1/4