Fazl Ullah and  Rahmat Ullah,  Optimization of Shale Gas Production by Advanced Hydraulic Fracturing.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2024, vol. 206(2). 63 - 70
    [viewed 28 April 2024]. Available from: https://publications.waset.org/pdf/10013518.