@misc{point+cloud+based+viewshed+generation+in+autocad+civil+3d,
    author = {Orlof, Jerzy},
    title = {Point cloud based viewshed generation in AutoCad Civil 3D},
    journal = {Technical Transactions},
    address = {Kraków},
    publisher = {<a href=\"http://www.wydawnictwo.pk.edu.pl/\" target=\"_blank\">Wydawnictwo PK</a>},
    date = {2017},
    number = {Y. 114, vol. 12}
}