GINEVIČIUS, Romualdas. Hierarchical structuring of processes and phenomena. Business: Theory and Practice, [S. l.], v. 8, n. 1, p. 14–18, 2007. DOI: 10.3846/btp.2007.03. Disponível em: https://journals.vilniustech.lt/index.php/BTP/article/view/11585. Acesso em: 9 may. 2025.