@inproceedings{Koli2017,
    author="Lonati, Violetta and Malchiodi, Dario and Monga, Mattia and Morpurgo, Anna",
    title="How presentation affects the difficulty of computational thinking tasks: an IRT analysis",
    
    booktitle="Proceedings of 17th Koli Calling International Conference on Computing Education Research",
    publisher="ACM",pages="60–69",
    year=2017},