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3. J. D. Franckowiak, and L. N. Barker, 1975 : Inheritance of testa color and color pattern in cowpea. Contribution from the Faculty of Agriculture, University of Ife, Ile-Ife, Nigeria, and the University of Wisconsin-Madison/USAIB contract project No. 620-11-110-742. (Unpublished).
4. J. D. Franckowiak, I. Fawole, K. M. Rawal, and W. H. Porter, 1975 : Eye pattern and flower colour modification in cowpea. Contribution from the Faculty of Agriculture University of Ife, Ile-Ife, Nigeria and IITA, Ibadan, Nigeria. (Unpublished).
5. International Institute of Tropical Agriculture (IITA) , 1974 : Cowpea Germplasm Catalog.