Casado Filho, Petrúcio Lopes. “Copyright Law Vs. Copyleft: Controversies Between Textbook Copyright and Private Photocopying”. The Journal of Intellectual Property – Contemporary Law and Constitution 2, no. 1 (February 1, 2013): 1–97. Accessed August 7, 2026. https://www.pidcc.com.br/pidcc/article/view/9.