Design Considerations for Highly Linear Electronically Tunable Resistor. - Kostas Vavelidis; Yannis P. Tsividis (ISCAS, 1993)

Six-terminal MOSFET's: modeling and applications in highly linear, electronically tunable resistors. - Kostas Vavelidis; Yannis P. Tsividis; Frank Op't Eynde; Yannis Papananos (IEEE J. Solid State Circuits, 1997)