J Reader, V Kaufman, J Sugar, JO Ekberg, U Feldman… - JOSA B, 1987 - opg.optica.org
New measurements have been made for wavelengths of the 3s–3p, 3p–3d, and 3d–4f
transitions of the sodiumlike ions Cu^ 18+, Zn^ 19+, Ga^ 20+, Ge^ 21+, As^ 22+, Se^ 23+ …