Jackson, Natalie, Michael S. Lewis-Beck, and Charles Tien. “Pollster Problems in the 2016 US Presidential Election: Vote Intention, Vote Prediction”. Italian Journal of Electoral Studies IJES - QOE 83, no. 1 (July 28, 2020): 17-28. Accessed March 7, 2021. https://oaj.fupress.net/index.php/qoe/article/view/9529.