Kumaraswamy, P. (1980). A generalized probability density function for double-bounded random processes.
Journal of Hydrology. 46(1-2): 79-88.
Jones, M.C. (2009). Kumaraswamy's distribution: A beta-type distribution with some tractability advantages.
Statistical Methodology. 6(1): 70-81.
Zhang, W. & Wei, H. (2008). Maximum likelihood estimation for simplex distribution nonlinear mixed models
via the stochastic approximation algorithm. The Rocky Mountain Journal of Mathematics, 38(5): 1863-1875.
You can also check the relevant wikipedia pages.