This WOCSDICE 2004 paper by Handel and Henning addresses 1/f frequency fluctuations and phase noise in MEMS (Micro-Electro-Mechanical Systems) resonators. The work analyzes the quantum and classical sources of frequency instability and phase noise in miniaturized mechanical resonators used as frequency references and timing elements, examining how fundamental 1/f noise processes limit the stability and accuracy of MEMS oscillators, with implications for timing applications, inertial sensors, and RF communication systems.