Xuexin Liu Wai-Shing Luk Yu Song Pushan Tang Xuan Zeng Robust Analog Circuit Sizing Using Ellipsoid Method and Affine Arithmetic. 203-208 2007 conf/aspdac/2007 ASP-DAC http://doi.ieeecomputersociety.org/10.1109/ASPDAC.2007.357986 db/conf/aspdac/aspdac2007.html#LiuLSTZ07