1988, Cushitic-Omotic: papers from the International Symposium on Cushitic and Omotic Languages (Marianne Bechhaus-Gerst, Fritz Serzisko; ISBN3-87118-890-5, page 167:
Hamar kʼalˀbe, Karo kalpo 'leaf'.
2000, Gezahegn Petros, The Karo of the lower Omo Valley: subsistence, social organisation and relations with neighbouring groups:
Despite their use of the Karo language, however, they keep relationships among themselves. Moguji young men travel together for hunting, make trips to Kuntama (one of the main sorghum fields), go to the forest to collect honey […]
2007, Encyclopedia of the world's endangered languages (Christopher Moseley), page 140:
Karo is the only member of the Tupi-Ramarama subbranch. The language is spoken by almost everyone in the two villages. Portuguese is learned as a second language and only used in contact situations.
2010, Nina Topintzi, Onsets: Suprasegmental and Prosodic Behaviour, page 39
2.2 Languages where the quality of onsets (QO) matters exclusively […] the presence of QO effects is evident in at least three languages: Pirahã, Arabela and Karo,2 but it is only the latter that also clearly lacks PO effects.