Kubanek, D., T. Freeborn, J. Koton, and N. Herencsar. “Evaluation of (1 + α) Fractional-Order Approximated Butterworth High-Pass and Band-Pass Filter Transfer Functions”. Elektronika Ir Elektrotechnika, vol. 24, no. 2, Apr. 2018, pp. 37-41, doi:10.5755/j01.eie.24.2.20634.