From the introduction: "This paper examines preliminary evidence regarding the type of the relationship obtaining between Peba-Yaguan and Zaparoan languages. My tentative conclusions are that certain features shared by the Peba-Yaguan and Zaparoan families may be due to a genetic connection, though independent origin cannot be ruled completely out. These features include phonological phenomena, certain transitivity-related verbal suffixes, and postpositional counterparts of some such suffixes."
Payne, Doris L.
"Evidence for a Yaguan-Zaparoan connection,"
Work Papers of the Summer Institute of Linguistics, University of North Dakota Session: Vol. 28, Article 4.
Available at: https://commons.und.edu/sil-work-papers/vol28/iss1/4