To cite irtrees in publications use:
Paul De Boeck, Ivailo Partchev (2012). IRTrees: Tree-Based Item Response Models of the GLMM Family. Journal of Statistical Software - Code Snippets, 48(1), 1-28. URL http://www.jstatsoft.org/v48/c01/.
Corresponding BibTeX entry:
@Article{, title = {IRTrees: Tree-Based Item Response Models of the GLMM Family}, author = {Paul {De Boeck} and Ivailo Partchev}, journal = {Journal of Statistical Software -- Code Snippets}, year = {2012}, volume = {48}, number = {1}, pages = {1--28}, url = {http://www.jstatsoft.org/v48/c01/}, }