TIEES 2021. International Scientific Web-conference. TIEES 2021: Trends and Innovations in E-Business, Education and Security : Ninth International Scientific Web-conference of Scientists and PhD. Students or Candidates : Reviewed Proceedings. Editors: Peter Schmidt, Zoltán Rajnai, Pavol Jurík ; reviewers: Erzsébet Ancza, Magdaléna Cárachová... [et al.]. 1st Edition. Bratislava : The Slovak Society for Economic Informatics, 2021. 189 s. [9,45 AH]. Dostupné na : <https://tiees.webconf.online/index.php/previous-conferences/2021> ISSN 2729-8493.