Efik  proper, also known as Riverain Ibibio, is the native language of the Efik people of Nigeria, where it is a national language. It is the official language of the Cross River State in Nigeria.
The name Efik is also used for Ibibio-Efik.
- ^ Efik at Ethnologue (18th ed., 2015)
- ^ Efik language at Ethnologue (14th ed., 2000).
- ^ Nordhoff, Sebastian; Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2013). "Efik". Glottolog. Leipzig: Max Planck Institute for Evolutionary Anthropology.
- ^ Laurie Bauer, 2007, The Linguistics Student’s Handbook, Edinburgh
- ^ Okon E. Essien, 1986, Ibibio names: their structure and their meanings