1. Hodges: ‘Analysis and design of digital integrated circuits’, Jackson, (McGraw Hill New York 1982)
2. Millman, J., and Taub, H.: ‘Pulse digital and switching waveforms’, (McGraw Hill New York 1970)
3. Millman, J., and Hilkias, C.C.: ‘Integrated electronics’, (McGraw Hill New York 1972)
4. Novel CMOS Schmitt trigger