I recently learned of David Fleck’s new monograph Panoan Languages and Linguistics, available online here through the American Museum of Natural History. Fleck provides an internal classification of the family, but perhaps the greatest service he has provided is to sort through the perplexing blizzard of Panoan ethnonyms one finds in the colonial and ethnographic literature, and in older classifications of Panoan languages. He also discusses language names that have been applied to both Panoan languages and non-Panoan ones (Katukina, anyone?), which is another source of confusion. This is a very useful reference to anyone who engages, however briefly, with Panoan linguistics.
Amazonian Linguistics 