@article {IOPORT.50218752,
    author       = {Mann, Anthony G. and Sheng, Chang and Luiten, Andre N.},
    title        = {Cryogenic sapphire oscillator with exceptionally high frequency stability},
    year         = {2001},
    journal      = {IEEE T. Instrumentation and Measurement},
    volume       = {50},
    number       = {2},
    pages        = {519-521},
    doi          = {10.1109/19.918181},
    identifier   = {50218752},
}