KETAKAR, V. B. The Sine and Cosine Series. The Journal of the Indian Mathematical Society, [S. l.], v. 5, n. 4, p. 133–135, 1913. DOI: 10.18311/jims/1913/17733. Disponível em: https://www.informaticsjournals.com/index.php/jims/article/view/17733. Acesso em: 5 may. 2024.