Boyko Berov, Plamen Ivanov, G. Frangov, Nikolai Dobrev, Miroslav Krastanov. "LIQUEFACTION SUSCEPTIBILITY OF QUATERNARY DEPOSITS IN BULGARIA." SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 17th International Multidisciplinary Scientific GeoConference SGEM2017, Science and Technologies in Geology, Exploration and Mining (2017): 499-506. https://doi.org/10.5593/sgem2017/12/s02.064