Sotner, R., Jerabek, J., Dostal, T. and Vrba, K. (2016) “Z-copy Voltage Controlled Current Follower Differential Input Transconductance Amplifier in Controllable Biquadratic Band-Pass Filter”, Elektronika ir Elektrotechnika, 22(4), pp. 32 - 36. doi: 10.5755/j01.eie.22.4.15911.