1.
De Boeck P, Bakker M, Zwitser R, Nivard M, Hofman A, Tuerlinckx F, et al. The Estimation of Item Response Models with the lmer Function from the lme4 Package in R. J. Stat. Soft. [Internet]. 2011 Mar. 9 [cited 2025 Dec. 6];39(12):1-28. Available from: https://www.jstatsoft.org/index.php/jss/article/view/v039i12