BARCZAK, A.; STEFANIUK, M. Comparative analysis of e-procurement systems. Studia Informatica. System and information technology, [S. l.], v. 11, n. 2, p. 5–13, 2008. Disponível em: https://czasopisma.uph.edu.pl/studiainformatica/article/view/2823. Acesso em: 5 may. 2024.