http://www.rogerblench.info/Language/Niger-Congo/VN/Igboid/IgbOP.htm (Any fulltext)
http://www.rogerblench.info/Language/Niger-Congo/VN/Igboid/Ogba%20Dictionary.pdf (Any fulltext)
Blench, R., & Ogba Language Committee (Eds.). (2013). Dictionary of Ogbà, an Igboid language of Southern Nigeria. Cambridge: N.A.