Organic Matter in the Early Toarcian Shales, Paris Basin, France: a Response to Environmental ChangesD. J. Hollander, G. Bessereau, S. Belin, A. Y. Huc and J. P. HouzayRev. Inst. Fr. Pét., 46 5 (1991) 543-562DOI: https://doi.org/10.2516/ogst:1991027