GRACIN, Josip; STIPETIĆ, Antun. Designing Postal Network Units. Promet - Traffic&Transportation, [S. l.], v. 21, n. 6, p. 387–394, 2012. DOI: 10.7307/ptt.v21i6.255. Disponível em: https://traffic2.fpz.hr/index.php/PROMTT/article/view/1527. Acesso em: 26 aug. 2025.