Statistical Modelling of Monthly Petroleum Product Sales: Trend, Seasonality and Stationarity Analysis of Premium Motor Spirit and Automotive Gas Oil in Plateau State, Nigeria PP:     1*Ali, H., 2Akanihu, C. N., 3Mwasho, Azi Danjuma, 3Fulus, F. D., & 4Wallen, Juliet Piapnaan GSAR Journal of Economics and Finance 2(10) PDF