WASET
    Ernst D. Schmitter,  Characterisation and Classification of Natural Transients.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2008, vol. 13(1). 5 - 8
    [viewed 28 March 2024]. Available from: https://publications.waset.org/pdf/7945.