https://www.sil.org/resources/archives/96100
https://www.sil.org/resources/archives/95606
https://www.sil.org/resources/archives/47663
https://www.sil.org/resources/archives/41307
Available: http://www.sil.org/silewp/2008/silewp2008-003.pdf. A paper copy may be made from the pdf