HYBKA , Małgorzata Magdalena. Federal Income Taxes in the United States - Tax Design and Fiscal Efficiency. Studia Oeconomica Posnaniensia, Poznan, Polska, v. 4, n. 4, p. 7–22, 2016. DOI: 10.18559/SOEP.2016.4.1. Disponível em: https://journals.ue.poznan.pl/soep/article/view/3429. Acesso em: 3 sep. 2026.