WASET
    Ernst D. Schmitter,  Analysing and Classifying VLF Transients.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2007, vol. 6(6). 68 - 68
    [viewed 11 May 2024]. Available from: https://publications.waset.org/pdf/2129.