The two oscillator circuits underneath are ideal for applying crystal oscillators in series or parallel manner: Large-repetition-amount and higher-electricity picosecond regenerative amplifier based on an individual bulk Nd:GdVO4 crystal A timing reference incorporating one-crystal-silicon micromechanical resonator with a quality aspect of more substantial than a million and a resonan... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html