. . . . . . . . "Case studies" . . . . . . "Language documentation and endangerment in Africa" . . . . "Language obsolescence." . . "Language obsolescence Africa." . . . . "Africa." . . "Linguistic change Case studies." . . "Endangered languages Africa." . . "Endangered languages Case studies." . . "Linguistic change Africa." . . "Linguistic change." . . "Endangered languages." . . "Language obsolescence Case studies." . .