LAICHAS, Tom. On My Desk: Why are textbooks expensive?. World History Connected, [S. l.], v. 3, n. 2, 2006. DOI: 10.13021/whc.v3i2.5109. Disponível em: https://journals.gmu.edu/whc/article/view/5109. Acesso em: 12 sep. 2025.