E., Derek G. Kerfoot (2005). „Nickel”. Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH Verlag GmbH & Co. KGaA. doi:10.1002/14356007.a17_157.
M. P. Fewell (1995). „The atomic nuclide with the highest mean binding energy”. American Journal of Physics. 63 (7): 653. doi:10.1119/1.17828.arhivirano
Georges, Audi; Bersillon O.; Blachot J.; Wapstra A.H. (2003). „The NUBASE Evaluation of Nuclear and Decay Properties”. Nuclear Physics A. Atomic Mass Data Center. 729: 3—128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
Georges, Audi; Bersillon O.; Blachot J.; Wapstra A.H. (2003). „The NUBASE Evaluation of Nuclear and Decay Properties”. Nuclear Physics A. Atomic Mass Data Center. 729: 3—128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
Kramida, A., Ralchenko, Yu., Reader, J., NIST ASD Team (2014). NIST Atomic Spectra Database, (ver. 5.2), National Institute of Standards and Technology, Gaithersburg, MD; da bi se došlo do podataka za nivo atoma nikla, potrebno je upisati "Ni I" u okvir Spectrum i kliknuti na link Retrieve data(језик: енглески)
M. P. Fewell (1995). „The atomic nuclide with the highest mean binding energy”. American Journal of Physics. 63 (7): 653. doi:10.1119/1.17828.arhivirano