OKONKWO, Charity Akuadi. Assessment of challenges in developing self-instructional course materials at the National Open University of Nigeria. The International Review of Research in Open and Distributed Learning, [S. l.], v. 13, n. 2, p. 221–231, 2012. DOI: 10.19173/irrodl.v13i2.930. Disponível em: https://www.irrodl.org/index.php/irrodl/article/view/930. Acesso em: 15 jul. 2024.