HAJDUOVÁ, Zuzana. The Impact of Diversification of Provided Services on the Efficiency of the Company. In Innovative Businesses and Start-ups in Current Business Environment. International Scientific Conference. Innovative Businesses and Start-ups in Current Business Environment : Abstracts Proceedings from International Scientific Conference. - Bratislava : Pan-European University, 2021. ISBN 978-80-89453-93-1, pp. 7. VEGA 1/0240/20.