CHARMAN, W N. Gradient-index Optics. Canadian Journal of Optometry, [S. l.], v. 44, n. 4, p. 8, 1982. DOI: 10.15353/cjo.v44i4.4245. Disponível em: https://openjournals.uwaterloo.ca/index.php/cjo/article/view/4245. Acesso em: 9 apr. 2025.