Can someone tell me if the article from professor Myers (1989) is a good/solid reference for defining what stationarity in geostatistics is? Myers, D. E. (1989) To Be or Not to Be... Stationary? That Is the Question. Mathematical Geology, Vol. 21, No. 3, 1989. Or with time, there were other nowadays more standard definitions of stationarity, or perhaps better explanations/articles about the topic?