Pengfei Wang, Chonghai Qi, Meishan Wang, Chuanlu Yang & jing Li. (2019). Theoretical Study of the Spectroscopic Constant and Anharmonic Force Field of $PO^-_2$.
            <i>Journal of Atomic and Molecular Sciences</i>. <i>6</i> (2).
            92-102.
         doi:10.4208/jams.040315.050415a