BHATTACHARYYA, G. POPSI Its Fundamentals and Procedure based on a General Theory of Subject Indexing Languages. Journal of Information and Knowledge, [S. l.], v. 16, n. 1, p. 1–34, 1979. DOI: 10.17821/srels/1979/v16i1/50472. Disponível em: https://srels.org/index.php/sjim/article/view/50472. Acesso em: 28 jul. 2025.