I. Sakho. (2019). A Modification of Atomic Orbital Theory and Its Application to $(1snl)^1L^{\pi}$ and $(nl^2)L^{\pi}$ Excited States of He-Like Ions.
            <i>Journal of Atomic and Molecular Sciences</i>. <i>1</i> (2).
            103-117.
         doi:10.4208/jams.022510.031010a