D. Biolek and V. Biolkova, “Universal Biquad Using CDTA Elements for Cascade Filter Design,” Proceeding of 7th International Multiconference on Circuits, Systems Communications and Computers (CSCC), Athens,7-9 July 2003, pp. 8-12.
 A. T. Bekri and F. Anday, “Nth-Order Low-Pass Filter Employing Current Differencing Transconductance Amplifiers,” Proceeding of the 2005 European Conference on Circuit Theory and Design, Cork, 28 August-2 September 2005, pp. 193-196. http://dx.doi.org/10.1109/ECCTD.2005.1523026
 D. Biolek and V. Biolkova, “CDTA-C Current-Mode Universal 2nd Order Filter,” Proceeding of the 5th WSEAS International Conference on Applied Informatics and Communications, Malta, 15-17 September 2005, pp. 411-414.
 W. Tanjaroen, T. Dumawipata, S. Unhavanich, W. Tangsrirat and W. Surakampontorn, “Design of Current Differencing Transconductance Amplifier and Its Application to Current-Mode KHN Iquad Filter,” Proceeding of ECTICON, Ubon Ratchathani, 10-13 May 2006, pp. 497-500.
 D. Prasad, D. R. Bhaskar and A. K. Singh, “Universal Current-Mode Biquad Filter Using Dual Output Current Differencing Transconductance Amplifier,” International Journal of Electronics and Communications, Vol. 63, No. 6, 2008, pp. 497-501.
 A. Uygur and H. Kuntman, “Design of a Current Differencing Transconductance Amplifier (CDTA) and Its Application on Active Filters,” SIU’2005: IEEE 13th Signal Processing and Communication Applications Conference, Kayseri, 16-18 May 2005, pp. 340-343.
 N. A. Shah, M. Quadri and S. Z. Iqbal, “Current Mode Multifunction Filter Using Current Differencing Transconductance Amplifier,” Indian Journal of Pure & Applied Physics, Vol. 45, No. 9, 2007, pp. 767-769.
 D. Biolek, V. Biolkova and Z. Kolka, “Single-CDTA (Current Differencing Transconductance Amplifier) CurrentMode Biquad Revisited,” WSEAS Transactions on Electronics, Vol. 5, No. 6, 2008, pp. 250-257.
 D. Biolek, E. Hancioglu and A. U. Keskin, “High-PerforMance Current Differencing Transconductance Amplifier and Its Application in Precision Current-Mode Rectification,” International Journal of Electronics and Communications, Vol. 62, No. 2, 2008, pp. 92-96. http://dx.doi.org/10.1016/j.aeue.2007.03.003