Xing Song, and Kamel Rekab. “Asymptotic Optimality of Three Stage Design for Estimating Product of Means With Applications in Reliability Estimation and Risk Assessment”. Journal of Advances in Applied & Computational Mathematics, vol. 3, no. 1, June 2016, pp. 8-19, doi:10.15377/2409-5761.2016.03.01.3.