McDaniel, Darl H. (1977). "Spin factoring as an aid in the determination of spectroscopic terms". Journal of Chemical Education. 54 (3): 147. Bibcode:1977JChEd..54..147M. doi:10.1021/ed054p147.
McDaniel, Darl H. (1977). "Spin factoring as an aid in the determination of spectroscopic terms". Journal of Chemical Education. 54 (3): 147. Bibcode:1977JChEd..54..147M. doi:10.1021/ed054p147.
NIST Atomic Spectrum Database For example, to display the levels for a neutral carbon atom, enter "C I" or "C 0" in the "Spectrum" box and click "Retrieve data".
"NIST Atomic Spectra Database Ionization Energies Form". NIST Physical Measurement Laboratory. National Institute of Standards and Technology (NIST). October 2018. Retrieved 28 January 2019. This form provides access to NIST critically evaluated data on ground states and ionization energies of atoms and atomic ions.