ANDREASIK, Jan. Ontology of Offers. Regional Barometer. Analyses & Prognoses, [S. l.], n. 3 (29), p. 33–39, 2012. DOI: 10.56583/br.1225. Disponível em: https://czaz.akademiazamojska.edu.pl/index.php/br/article/view/1225. Acesso em: 14 may. 2025.