WILEY, David; HILTON III, John Levi; ELLINGTON, Shelley; HALL, Tiffany. A preliminary examination of the cost savings and learning impacts of using open textbooks in middle and high school science classes. The International Review of Research in Open and Distributed Learning, [S. l.], v. 13, n. 3, p. 262–276, 2012. DOI: 10.19173/irrodl.v13i3.1153. Disponível em: https://www.irrodl.org/index.php/irrodl/article/view/1153. Acesso em: 20 apr. 2024.