Compact CMOS circuits for high-speed continuous-time linear weighted voltage addition. - Jaime Ramírez-Angulo; Francisco Ledesma (ISCAS (1), 2001)

The universal opamp and applications in continuous-time resistorless and capacitorless linear weighted voltage addition. - Jaime Ramírez-Angulo; Francisco Ledesma (IEEE Trans. Circuits Syst. II Express Briefs, 2006)