BRABEC, Jiří; HELMICH, Martin. Development of an Ultralight with a Ducted Fan. Acta Polytechnica, [S. l.], v. 52, n. 5, 2012. DOI: 10.14311/1624. Disponível em: https://ojst.is.cvut.cz/ojs/index.php/ap/article/view/1624.. Acesso em: 31 may. 2025.