Kuen-Ming Shu and  Cheng-Yu Chen,  Innovation and Analysis of Vibrating Fork Level Switch.   journal   = {International Journal of Mechanical and Mechatronics Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2016, vol. 116(8). 1493 - 1497
    [viewed 14 November 2019]. Available from: https://publications.waset.org/pdf/10005142.