Sarracino, Francesco, and Malgorzata Mikucka. “Bias and Efficiency Loss in Regression Estimates Due to Duplicated Observations: A Monte Carlo Simulation”. Survey Research Methods 11, no. 1 (April 10, 2017): 17-44. Accessed August 12, 2022. https://ojs.ub.uni-konstanz.de/srm/article/view/7149.