Juan A. López Carlos Carreras Octavio Nieto-Taladriz Improved Interval-Based Characterization of Fixed-Point LTI Systems With Feedback Loops. 1923-1933 2007 26 IEEE Trans. on CAD of Integrated Circuits and Systems 11 http://dx.doi.org/10.1109/TCAD.2007.896306 db/journals/tcad/tcad26.html#LopezCN07