In researching the information portrayed in this website, I have used many sources of information:
Morgan Electroceramics
PARC Research
Piezo Systems, Inc.
American Piezo
Physike Instrumente
Interfacing Piezo Film to Electronics
efunda: Engineering Fundamentals
Everswitch
Piezo Kinetics
New Scientist vol 127 issue 1725 - 14 July 90