Pople79

J. A. Pople, K. Raghavachari, H. B. Schlegel, and J. S. Binkley, “Derivative Studies in Hartree-Fock and Møller-Plesset Theories,” Int. J. Quantum Chem., Quant. Chem. Symp., S13 (1979) 225-41. DOI: 10.1002/qua.560160825