Thanh, N. V., N. T. N. Anh, and N. A. Tuan. “Geometric Structure, Electronic Structure, and Spin Transition of Fe<SUP>2+</SUP> Spin-Crossover Molecules”. Communications in Physics, vol. 22, no. 4, Jan. 2013, p. 309, doi:10.15625/0868-3166/22/4/2365.