Rathke, Alex. “An Examination of Expected Goals and Shot Efficiency in Soccer”. Journal of Human Sport and Exercise 12, no. 2proc (August 29, 2017): S514-S529. Accessed April 20, 2024. https://www.jhse.ua.es/article/view/2017-v12-n2-proc-examination-expected-goals-shot-efficiency-socc.