Nõtre (also called 'Boulba') is a language of northern Benin. It is spoken in S'epounga and maybe other villages just north of Tanguiéta in the Département de l'Atakora.  

It is mostly known from three articles by R.P. André Prost from 1971, 1974 and 1975.  I have collated the language data from the latter two, respectively:

 Le Nõtre, langue des Nõtǝba dits Bulba. B.I.F.A.N. XXXVI sér. B n°.3 pp. 628-659 

and 

Vocabulaires comparés des langues de l'Atakora B.I.F.A.N. 37 sér. B n°. 2  pp. 412-448

for inclusion in the comparative dictionary.