1. R. N. Clayton and E. T. Degens, “Use of carbon isotope analyses of carbonates for differentiating freshwater and marine sediments,” Am. Assoc. Pet. Geol. Bull. 43, 890–897 (1959).
2. H. Craig, “The geochemistry of stable carbon isotopes,” Geochim. Cosmochim. Acta 3, 53–92 (1953).
3. Stable isotope distribution in carbonates;E. T. Degens,1967
4. S. I. Dworkin, L. Nordt, and S. Atchley, “The isotope chemistry of quartz and organic matter in silicified wood, Petrified Forest National Park, Arizona,” in Proceedings of the 2014 Annual Meeting of the Geological Society of America, (Vancouver, 2014).
5. W. El-Saadawi, M. M. Kamal-El-Din, Y. Attia, and M. M. El-Faramawi, “The wood flora of the Cairo Petrified Forest, with five Paleogene new legume records for Egypt,” Rev. Palaeobot. Palynol. 167, 184–195 (2011).