(1)
De Boeck, P.; Bakker, M.; Zwitser, R.; Nivard, M.; Hofman, A.; Tuerlinckx, F.; Partchev, I. The Estimation of Item Response Models With the Lmer Function from the Lme4 Package in R.
J. Stat. Soft.
2011
,
39
, 1-28.