MinQiang Li, XianHe Huang, Feng Tan, YanHong Fan and Xun Liang, "A novel microcomputer temperature-compensating method for an overtone crystal
oscillator," in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, vol.
The oscillator provides a lifetime stability of [+ or -]25 ppm for all conditions over -40 [degrees]C to +85 [degrees]C and touts an RMS jitter of <1 ps (12 kHz to 20 MHz) by using a 3rd overtone crystal
(3.) Bartram, C., "Notes on the Driscoll VHF Overtone Crystal
Oscillator and a New Low-Noise VHF Crystal Oscillator Topology," http://www.christopherbartramrfdesign.com/blaenffos/oscillator/VLNO.pdf
From 106.25 MHz to 170 MHz, this was accomplished two ways, the least expensive of which was using a third overtone crystal
. The other was the advent of inverted mesa fundamental crystals.