1. (1) Johnson, H. W., Robinson, H. F., and Comstock, R.E., (1955). Estimates of genetic and environmental variability in soybean. Agronomy Journal, 47 (7): 314 – 318.
2. (2) Ubi, E. B., Mignouna, H., and Obigbesan, G., (2001). Heritable relationships and variability of yield and yield components in vegetable cowpea. African Crop Science Journal, 3 (1): 23 – 28.
3. (3) Omoigui, L. O., Ishiyaku, M. F., Kamara, A. Y., Alabi, S. O., and Mohammed, S. G., (2006). Genetic variability and heritability studies of some reproductive traits in cowpea (Vigna unguiculata L. Walp). African Journal of Biotechnology, 5 (13): 1191 – 1195.
4. (4) Ajayi, A. T., and Adesoye, A. I. (2013). Cluster analysis technique for assessing variability in cowpea (Vigna unguiculata L. Walp) accessions from Nigeria. Ratar. Povrt. 50 (2): 1 – 7.
5. (5) Ajayi, A. T., Osekita, O. S., and Osaghae, S. O. (2014). Variability among some accessions of cowpea (Vigna unguiculata L. Walp) in Nigeria based on the expression of quantitative traits. Futa Journal of Research in Science (in press).