Business and Innovation in Business Activities. International Scientific Conference. Business and Innovation in Business Activities XIII. : Proceedings of Scientific Papers from International Scientific Conference, Organized on April 26, 2018 in Prešov. Reviewers: Juraj Rákoš, Elena Širá. Mainz : Logophon Verlag, 2018. 145 s. IG-KEMM-01/2016-3.3.9. ISBN 978-3-936172-54-6.