DIÓFÁSI, Orsolya; VALKÓ, László. Step by Step Towards Mandatory Green Public Procurement. Periodica Polytechnica Social and Management Sciences, [S. l.], v. 22, n. 1, p. 21–27, 2014. 10.3311/PPso.2151. Disponível em: https://pp.bme.hu/so/article/view/2151. Acesso em: 23 apr. 2024.