| Ernst, Urs | Description tonologique de l’énoncé nominal associatif en kakɔ | 1991 | SIL International Publications in Linguistics | Linguistics |
| Patman, Frankie | Tone in the Nugunu verb phrase | 1991 | SIL International Publications in Linguistics | Linguistics |
| Anderson, Stephen C., editor | Tone in five languages of Cameroon | 1991 | SIL International Publications in Linguistics | Linguistics |
| Heath, Daniel | Tone in the Makaa associative construction | 1991 | SIL International Publications in Linguistics | Linguistics |
| Wilkendorf, Patricia | Floating high tones in Nɔmaándɛ locatives | 1991 | SIL International Publications in Linguistics | Linguistics |
| Swackhamer, Jeanette | Tonal behavior of Podoko verbs in independent clauses | 1991 | SIL International Publications in Linguistics | Linguistics |
