Li, X. ., and J. . Zeng. “A Novel Dual-Band Microstrip Bandpass Filter Design and Harmonic Suppression”. Applied Computational Electromagnetics Society Journal (ACES), vol. 28, no. 04, Oct. 2021, pp. 348-52, https://journals.riverpublishers.com/index.php/ACES/article/view/11627.