PLease find the ARRL Radio Amateur's Handbook. Issued annually, since ~1980 you can find several types of oscillators suitable to use overtone crystals.
I was always successful in using a simple one transistor, with a harmonic LC circuit in collector, base grounded by the crystal, and emitter to ground with a ~1 kOhm resistor, WITH a 3-30 pF trimmer in parallel.This trimmer is tuned to select a particular harmonic (crystal overtone).
The output typically was ~1...10 mW at the crystal overtone frequency, and up to 30 mW if I tuned the emitter trimmer to a lower frequency. I had never any problem, used Ge and Si RF transistors.