KLEEFELD, Frieder. Complex Covariance. Acta Polytechnica, Prague, Czech Republic, v. 53, n. 3, 2013. DOI: 10.14311/1809. Disponível em: https://ojs.cvut.cz/ojs/index.php/ap/article/view/1809. Acesso em: 22 jan. 2025.