Fox, John, and Jangman Hong. “Effect Displays in R for Multinomial and Proportional-Odds Logit Models: Extensions to the Effects Package”. Journal of Statistical Software 32, no. 1 (October 14, 2009): 1–24. Accessed November 21, 2024. https://www.jstatsoft.org/index.php/jss/article/view/v032i01.