"Introduction to Quartz Frequency Standards," John R Vig, October 1992.

Abstract: More than one billion (i.e., 109) quartz crystal oscillators are produced annually for applications ranging from inexpensive watches and clocks to radionavigation and spacecraft tracking systems. The fundamentals of quartz oscillators are reviewed in this report, with emphasis on quartz frequency standards (as opposed to inexpensive clock oscillators). The subjects discussed include: crystal resonators and oscillators, oscillator types, and the characteristics and limitations of temperature-compensated crystal oscillators (TCXO) and oven-controlled crystal oscillators (OCXO). The oscillator instabilities discussed include: aging, noise, frequency vs. temperature, warmup, acceleration effects, magnetic field effects, atmospheric pressure effects, radiation effects, and interactions among the various effects. Guidelines are provided for oscillator comparison and selection. Discussions of specifications are also included, as are references and suggestions for further reading.


MIL-PRF-55310,General Specification For Oscillator, Crystal Controlled. 

Abstract: This specification covers the general requirements for quartz crystal oscillators used in electronic equipment. The crystal oscillators covered by this specification are unique due to the fact that these devices must be able to operate satisfactorily in systems under demanding conditions such as: 20 g's vibration, 100 g's of shock, 24 hours of salt spray, wide temperature range (e.g., -55°C to +85°C) and low noise under vibration. In addition, these requirements are verified under a qualification system. Commercial components are not designed to withstand these Environmental conditions.