http://www-01.sil.org/mexico/workpapers/scans/WS001i-WS012i-WorkpaperScans.htm|lire en ligne=http://www.sil.org/mexico/workpapers/scans/WS11/WS1106-PiperM.pdf (fr)
http://www-01.sil.org/mexico/workpapers/scans/WS001i-WS012i-WorkpaperScans.htm|lire en ligne=http://www.sil.org/mexico/workpapers/scans/WS11/WS1106-PiperM.pdf (fr)