http://proquest.umi.com/pqdweb?did=748623521&sid=2&Fmt=2&clientId=56146&RQT=309&VName=PQD (Any fulltext)
yagua_payne1985_o.pdf (Any fulltext), 13MB
Payne, D. L. (1985). Aspects of the grammar of Yagua: a typological approach. PhD Thesis, UMI, Ann Arbor.