W. Ostrowski, K. Bakula, R. Zaplata. "A NEW LOOK AT HISTORIC FORTIFICATIONS - MEDIEVAL CASTLES AND AIRBORNE LASER SCANNING." International Multidisciplinary Scientific Conference on Social Sciences and Arts SGEM2014, Book 3 (2014). https://doi.org/10.5593/sgemsocial2014/b31/s9.040