Curtis, David; Fabryka-Martin, June; Paul, Dixon; Cramer, Jan (1999), "Nature's uncommon elements: plutonium and technetium", Geochimica et Cosmochimica Acta, 63 (2): 275–285, Bibcode:1999GeCoA..63..275C, doi:10.1016/S0016-7037(98)00282-8
Wilcken, K.~M.; Barrows, T.T.; Fifield, L.K.; Tims, S.G.; Steier, P. (June 2007), "AMS of natural 236U and 239Pu produced in uranium ores", Nuclear Instruments and Methods in Physics Research B, 259: 727–732, Bibcode:2007NIMPB.259..727W, doi:10.1016/j.nimb.2007.01.210Pemeliharaan CS1: Banyak nama: authors list (link)
harvard.edu
adsabs.harvard.edu
Curtis, David; Fabryka-Martin, June; Paul, Dixon; Cramer, Jan (1999), "Nature's uncommon elements: plutonium and technetium", Geochimica et Cosmochimica Acta, 63 (2): 275–285, Bibcode:1999GeCoA..63..275C, doi:10.1016/S0016-7037(98)00282-8
Wilcken, K.~M.; Barrows, T.T.; Fifield, L.K.; Tims, S.G.; Steier, P. (June 2007), "AMS of natural 236U and 239Pu produced in uranium ores", Nuclear Instruments and Methods in Physics Research B, 259: 727–732, Bibcode:2007NIMPB.259..727W, doi:10.1016/j.nimb.2007.01.210Pemeliharaan CS1: Banyak nama: authors list (link)
jrc.it
esarda2.jrc.it
"Salinan arsip"(PDF). Diarsipkan dari versi asli(PDF) tanggal 2011-07-22. Diakses tanggal 2015-12-29.
web.archive.org
"Salinan arsip"(PDF). Diarsipkan dari versi asli(PDF) tanggal 2011-07-22. Diakses tanggal 2015-12-29.