1. Abeywardena, V. (1962). Studies on biennial bearing tendency in coconut. 1. Measurement of bienniality in coconut.Ceylon Coconut Quarterly,13, 112–128.
2. Abeywardena, V. (1964). The measurement of repeatability of seasonal patterns.Ceylon Coconut Quarterly,14, 87.
3. Fisher, R. A. And Yates, F. (1938).Statistical Tables. Oliver and Boyd: London.
4. Kendall, M. G. (1957).A Course in Multivariate Analysis. Charles Griffin & Co., Ltd., London.
5. Lawley, D. C. (1956). Tests of significance for the latent roots of covariance and correlation matrices.Biometrika,43, 128–136.