As a result, a large number of current mode active elements such as operational transconductance amplifier (OTA), current conveyor (CC), current controlled conveyor (CCC), current feedback amplifier (CFOA), operational transresistance amplifier
(OTRA), differential voltage current conveyor (DVCC), current differencing buffered amplifier (CDBA), current differencing transconductance amplifier (CDTA), and voltage differencing transconductance amplifier (VDTA) are published.
From internal structure implementation point of view, the current subtractor (CS) with current differencing capability ,  forms one of the most important sub-stages of recently proposed high-performance CM active building blocks (ABBs) such as current differencing transconductance amplifier (CDTA) , , , current differencing buffered amplifier (CDBA) , , , , operational transresistance amplifier (OTRA) , , or second-generation differential current conveyor (DCCII) -.
Soliman, "A modified CMOS differential operational transresistance amplifier (OTRA)", AEU - Int.
Grounded resistance/capacitance-controlled sinusoidal oscillators using operational transresistance amplifier
. In WSEAS Transactions on Circuits and Systems, Vol.