Nasser Erfani Majd and  Mojtaba Lotfizad,  A Novel Low Power Digitally Controlled Oscillator with Improved linear Operating Range.   journal   = {International Journal of Electrical and Computer Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2011, vol. 51(3). 356 - 361
    [viewed 25 October 2021]. Available from: https://publications.waset.org/pdf/6238.