Rosetta Project: Yaqui - Scanned-in documents on the Yaqui language including two glossed texts. - http://www.rosettaproject.org/archive/yaq/view?searchterm=yaqui
Wikipedia: Yaqui - Article including a phonological inventory and grammar information. - http://en.wikipedia.org/wiki/Yaqui_language
Yaqui Language and the Yaqui Indian Tribe - Pronunciation guide, language learning worksheets, and cultural information. - http://www.native-languages.org/yaqui.htm
Ethnologue: Yaqui - Basic demographic and linguistic information. - http://www.ethnologue.com/show_language.asp?code=yaq