1. Geochemical evidence for Paleozoic oil in Lower Cretaceous O Sandstone, northern Denver basin;Clayton;Bull. Am. Assoc. Pet. Geol.,1989
2. Source rock evaluation, oil-source rock correlation, and kinetic modeling—San Juan Sag, Colorado;Clayton;Bull. Am. Assoc. Pet. Geol.,1990
3. Effects of weathering on biological marker and aromatic hydrocarbon composition of organic matter in Phosphoria shale outcrop;Clayton;Geochim. Cosmochim. Acta,1987
4. Petrography and fluorescence properties of resinite macerals from western U.S. coals;Crelling,1982
5. Oil potential of coals—a geochemical approach;Durand,1983