GOPINATH, M. A.; MALHOTRA, V. K. Geographical Schedule in CC, UDC, and DC. Journal of Information and Knowledge, [S. l.], v. 3, n. 2, p. 168–196, 1966. DOI: 10.17821/srels/1966/v3i2/49145. Disponível em: https://srels.org/index.php/sjim/article/view/49145. Acesso em: 9 apr. 2025.