Duy, Trần Hữu, et al. “UNIVERSAL VOLTAGE-MODE BIQUADRATIC FILTER SYNTHESIS USING NODAL ADMITTANCE MATRIX EXPANSION”. Dalat University Journal of Science, vol. 6, no. 3, Sept. 2016, pp. 293-15, https://doi.org/10.37569/DalatUniversity.6.3.74(2016).