If the reader wants to know the details of MIRT, please refer to the paper: Multidimensional item response theory models
@incollection{reckase2009multidimensional,
title={Multidimensional item response theory models},
author={Reckase, Mark D},
booktitle={Multidimensional item response theory},
pages={79--112},
year={2009},
publisher={Springer}
}