CU Linguistics professor Zygmunt Frajyzngier and an international team of researchers have produced a  of the Chadic language Hdi. The book is the first trilingual dictionary of this endangered language. The dictionary is preceded by a short grammatical sketch, and contains French-Hdi-English and English-Hdi French indexes. Most verbs are illustrated by examples. Hdi (gwáɗ-á ³æ»åà ‘anguage of Hdi’ or simply ³æ»åà‘in Hdi’) is a Central Chadic language spoken in the Far North Province of Cameroon. Hdi is the predominant language used in the city of Tourou, located on the border between Cameroon and Nigeria. The estimated number of current speakers of Hdi ranges between 10,000 and 29,000 (). The dictionary is based on fieldwork begun by Zygmunt Frajzyngier in 1991 and incorporates data from Paul Eguchi’s Matériaux pour servir à l'étude de la langue hidé: VocabulaireÌý(1971).
Frajzyngier, Zygmunt, Roger Prafé, Paul Eguchi, Shaae Schwabauer, with Erin Shay and Henry Tourneux. 2015.  A Dictionary of Hdi: A Central Chadic Language of Cameroon. Cologne: Koeppe