Wouter A. Serdijn J. Mulder Michiel H. L. Kouwenhoven Arthur H. M. van Roermund A low-voltage translinear second-order quadrature oscillator. 701-704 1999 conf/iscas/1999 ISCAS (2) http://doi.ieeecomputersociety.org/10.1109/ISCAS.1999.780861 db/conf/iscas/iscas1999-2.html#SerdijnMKR99