1. Characterization of crude oils by new trace-metal indices;Abu-Elgheit;Amer. Chem. Soc., Div. Petrol. Chem., Preprints,1979
2. Vertical migration of oil in Iraqi oil fields: evidence based on vanadium and nickel concentrations;Al-Shahristani;Geochim. Cosmochim. Acta,1972
3. Limits of the natural environment in terms of pH and oxidation-reduction potential;Baas Becking;J. Geol.,1960
4. Alteration of crude oil by waters and bacteria—evidence from geochemical and isotope studies;Bailey;Amer. Assoc. Petrol. Geol. Bull.,1973
5. Tetrapyrrole pigments in Cretaceous sediments from the Bay of Biscay, IPOD Leg 48, hole 402A;Baker,1979