Pratikha, Aulia Riski, et al. “Electron’s Position Expectation Values and Energy Spectrum of Lithium Ion (Li^(2+)) on Principal Quantum Number n≤3”. Jurnal Penelitian Pendidikan IPA, vol. 8, no. 1, Jan. 2022, pp. 252-6, doi:10.29303/jppipa.v8i1.840.