Orr, P. J.; Kearns, S. L.; Briggs, D. E. G. (2009). "Elemental mapping of exceptionally preserved 'carbonaceous compression' fossils". Palaeogeography, Palaeoclimatology, Palaeoecology. 277 (1–2): 1–8. Bibcode:2009PPP...277....1O. doi:10.1016/j.palaeo.2009.02.009.
google.com
Wittry, David B. (1958). "Electron Probe Microanalyzer", US Patent No 2916621[dead link], Washington, DC: U.S. Patent and Trademark Office
Orr, P. J.; Kearns, S. L.; Briggs, D. E. G. (2009). "Elemental mapping of exceptionally preserved 'carbonaceous compression' fossils". Palaeogeography, Palaeoclimatology, Palaeoecology. 277 (1–2): 1–8. Bibcode:2009PPP...277....1O. doi:10.1016/j.palaeo.2009.02.009.