Denk, Michaela, and Peter Hackl. “Data Integration: Techniques and Evaluation”. Austrian Journal of Statistics 33, no. 1&2 (April 3, 2016): 135–152. Accessed January 31, 2023. https://www.ajs.or.at/index.php/ajs/article/view/vol33%2C%20no1%262%20-%208.