https://www.sil.org/resources/archives/47893
https://www.sil.org/resources/archives/47919
https://www.sil.org/resources/archives/47455
https://www.sil.org/resources/archives/50138
Available: http://www.sil.org/silesr/2009/silesr2009-004.pdf. A paper copy may be made from the pdf
https://www.sil.org/resources/archives/47435