THE INFLUENCE OF COVID-19 ON THE CHOICE OF ECONOMICALLY OPTIMAL VARIANT OF THE AEROPLANE. Perner’s Contacts, [S. l.], v. 16, n. 2, 2021. DOI: 10.46585/pc.2021.2.1722. Disponível em: https://pernerscontacts.upce.cz/index.php/perner/article/view/1722. Acesso em: 5 mar. 2026.