Fanning, Thomas H. (May 3, 2007). "Sodium as a Fast Reactor Coolant"(PDF). Ne.doe.gov. Office of Nuclear Energy | Department of Energy | University of Chicago, Argonne. Archived from the original(PDF) on 2013-01-13. Retrieved 2014-01-24.
Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics. 71 (2): 299. Bibcode:1965NucPh..71..299M. doi:10.1016/0029-5582(65)90719-4. "The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk248 with a half-life greater than 9 [years]. No growth of Cf248 was detected, and a lower limit for the β− half-life can be set at about 104 [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."
Poplavskii, V. M.; Chebeskov, A. N.; Matveev, V. I. (2004-06-01). "BN-800 as a New Stage in the Development of Fast Sodium-Cooled Reactors". Atomic Energy. 96 (6): 386–390. doi:10.1023/B:ATEN.0000041204.70134.20. S2CID96585192.
Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics. 71 (2): 299. Bibcode:1965NucPh..71..299M. doi:10.1016/0029-5582(65)90719-4. "The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk248 with a half-life greater than 9 [years]. No growth of Cf248 was detected, and a lower limit for the β− half-life can be set at about 104 [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."
Poplavskii, V. M.; Chebeskov, A. N.; Matveev, V. I. (2004-06-01). "BN-800 as a New Stage in the Development of Fast Sodium-Cooled Reactors". Atomic Energy. 96 (6): 386–390. doi:10.1023/B:ATEN.0000041204.70134.20. S2CID96585192.
Fanning, Thomas H. (May 3, 2007). "Sodium as a Fast Reactor Coolant"(PDF). Ne.doe.gov. Office of Nuclear Energy | Department of Energy | University of Chicago, Argonne. Archived from the original(PDF) on 2013-01-13. Retrieved 2014-01-24.