*{{Citationchú thích | pmid=17830216 | last=Richardson | first= | publication-date=1913 Jul 11 | year=1913 | title=The Emission Of Electrons From Tungsten At High Temperatures: An Experimental Proof That The Electric Current In Metals Is Carried By Electrons. | volume=38 | issue=967 | periodical= | pages=57–61 | doi=10.1126/science.38.967.57 | journal=Science | first1=OW|bibcode = 1913Sci....38...57R }}
*{{Citationchú thích | pmid=17800821 | last=Richardson | first= | publication-date=1912 Jul 12 | year=1912 | title=The Laws Of Photoelectric Action And The Unitary Theory Of Light (Lichtquanten Theorie). | volume=36 | issue=915 | periodical= | pages=57–58 | doi=10.1126/science.36.915.57-a | journal=Science | first1=OW|bibcode = 1912Sci....36...57R }}