Delipetrev, Marjan, Doneva, Blagica, Delipetrov, Todor, Panov, Zoran, Dimov, Gorgi. "TIME VARIATION OF THE GEOMAGNETIC FIELD ON THE TERRITORY OF THE REPUBLIC OF MACEDONIA IN THE LAST 50 YEARS." SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 13th SGEM GeoConference on SCIENCE AND TECHNOLOGIES IN GEOLOGY, EXPLORATION AND MINING, 2013, pp. 935 - 942 pp. https://doi.org/10.5593/sgem2013/ba1.v2/s05.033