Localized basis orbitals: minimization of 2-electron integrals array and orthonormality of basis set.
Anikin NA, Bugaenko VL, Frash MV, Gorb L, Leszczynski J. Localized basis orbitals: minimization of 2-electron integrals array and orthonormality of basis set. J Comput Chem. 2003 Jul 15; 24(9):1132-41.