The 2 oscillator circuits under are well suited for making use of crystal oscillators in collection or parallel method: Substantial-repetition-level and large-ability picosecond regenerative amplifier according to one bulk Nd:GdVO4 crystal A timing reference incorporating a single-crystal-silicon micromechanical resonator with a top quality component of larger than one million plus https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html