SOJKA, Pavol. Online Scanning and Break-Through Attempts Conducted by Foreign Attackers to Internal Online Systems and the Costs Associated with Them. In EDAMBA 2020. International Scientific Conference for Doctoral Students and Post-Doctoral Scholars. EDAMBA 2020 : International Scientific Conference for Doctoral Students and Post-Doctoral Scholars. - Bratislava : Vydavateľstvo EKONÓM, 2020. ISBN 978-80-225-4794-9, pp. 620-629 online.