S. HASSAN, Abbas. Comparative Study of Different Types of an Active Filter. Journal of Engineering and Sustainable Development, Baghdad, Iraq, v. 15, n. 4, p. 49–60, 2011. Disponível em: https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1307.. Acesso em: 26 apr. 2025.