Antia, A. D., I. B. Okon, E. B. Umoren, and C. N. Isonguyo. “Relativistic Study of the Spinless Salpeter Equation With a Modified Hylleraas Potential”. Ukrainian Journal of Physics, vol. 64, no. 1, Jan. 2019, p. 27, doi:10.15407/ujpe64.1.27.