HILTON III, John Levi; WILEY, David. Open access textbooks and financial sustainability: A case study on Flat World Knowledge. The International Review of Research in Open and Distributed Learning, [S. l.], v. 12, n. 5, p. 18–26, 2011. DOI: 10.19173/irrodl.v12i5.960. Disponível em: https://www.irrodl.org/index.php/irrodl/article/view/960. Acesso em: 23 apr. 2024.