PARDHASARADHI, T. V. A condition for achromatism of three lenses. Defence Science Journal, [S. l.], v. 11, n. 2, p. 112–115, 2014. DOI: 10.14429/dsj.11.6804. Disponível em: https://publications.drdo.gov.in/ojs/index.php/dsj/article/view/6804. Acesso em: 7 jul. 2025.