Wen-Chi Liu,  The Study on the Stationarity of Energy Consumption in US States: Considering Structural Breaks, Nonlinearity, and Cross- Sectional Dependency.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    August 2013, vol. 80(8). 1310 - 1330
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/16174.