Orupabo, George J. 1980. Okrika. In Kropp Dakubu, M. E. (ed.), West African language data sheets, vol. 2. Leiden: West African Linguistic Society and African Studies Centre.
@misc{6915,
author = {Orupabo, George J.},
title = {Okrika. In Kropp Dakubu, M. E. (ed.), West African language data sheets, vol. 2. Leiden: West African Linguistic Society and African Studies Centre.},
year = {1980}
}