GWÓŹDŹ, K. Assessing the non-financial investment profitability with variable discount rate. Oeconomia Copernicana, [S. l.], v. 6, n. 4, p. 123–138, 2015. DOI: 10.12775/OeC.2015.032. Disponível em: http://economic-research.pl/Journals/index.php/oc/article/view/159. Acesso em: 20 jan. 2022.