1. Electrical Measurement: Quartz as a Frequency reference;Schrüfer,1992
2. Quartz Crystal Theoryhttp://www.omig.pl/en/crystal_units.html
3. Theory and Properties of Piezoelectric Resonators and Waves;Meeker,1985
4. Crystals for Quartz Resonators;Brice;Reviews of Modern Physics,1985
5. Design of Crystal and Other Harmonic Oscillators;Parzen,1983