Ausubel, J.H. <https://pure.iiasa.ac.at/view/iiasa/1698.html>, Victor, D.G. <https://pure.iiasa.ac.at/view/iiasa/1642.html>, & Wernick, I.K.  (1995).  The environment since 1970.   Consequences: The Nature and Implications of Environmental Change 1 (3) 3-15.