Piezo Theory
- Discusses the historic background, piezoelectric constants, soft versus hard ceramics, behavior of elements, resonance frequencies, applications, new materials and applications.
- http://www.americanpiezo.com/piezo_theory/

NPL: Sensors & Functional Materials Group - Publications about piezoelectric materials
- the UK's national standards laboratory, who look after the basic units of measurement such as time, mass and length which ensure consistency and traceability of measurements.
- http://www.npl.co.uk/npl/cmmt/functional/publications.html

Theory and Applications of Piezo Ceramic Actuators and PZT NanoPositioning Systems
- Physikinstrumente (Germany) - very good information about piezo actuators and positioning systems.
- http://www.physikinstrumente.com/tutorial/index.html

Smart Material, Corp. (Germany)
- Advanced piezoelectric Materials and Components
- http://www.smart-material.com

Introduction to Bending Elements
- Piezo Systems Corp.
- http://www.piezo.com/bendedu.html

Recommended Reading about Piezoelectricity
- PIEZO SYSTEMS, INC.
- http://www.piezo.com/reading.html