RAMACHANDRAN, R. Patent Classification System in India, Japan, United Kingdom and USA. Journal of Information and Knowledge, [S. l.], v. 26, n. 4, p. 245–263, 2014. DOI: 10.17821/srels/1989/v26i4/49326. Disponível em: https://srels.org/index.php/sjim/article/view/49326. Acesso em: 4 mar. 2025.