Èdè Ịzọn tàbí Izon tàbí Izo tàbí Ijo tàbí Uzo tàbí Ijaw jẹ́ èdè Ijọidi ní Nàìjíríà (ní àwọn Ìpínlẹ̀ Bàyélsà àti Dẹ́ltà àti Òndó àti Èkìtì). Williamson, Kay, and A. O. Timitimi (edd.). 1983. Short Ịzọn–English dictionary. (Delta Series No. 3) Port Harcourt: University of Port Harcourt Press. Williamson, Kay. 1965 (2nd ed. 1969). A grammar of the Kolokuma dialect of Ịjọ. (West African Language Monographs, 2.) London: C.U.P. Williamson, Kay. 1975. Metre in Ịzọn funeral dirges. Ọ̀dụ̀má 2:2.21–33. Williamson, Kay. 1991. "The tense system of Ịzọn." In: The tense systems of Nigerian languages and English. Edited by Okon E. Essien. Afrikanistische Arbeitspapiere (AAP) 27.145–167. Williamson, Kay. 2004. "The language situation in the Niger Delta." Chapter 2 in: The development of Ịzọn language, edited by Martha L. Akpana, 9–13.