Andrews, D. L. and Ghoul, W. A. (1982) Irreducible fourth-rank Cartesian tensors. Physical Review A, 25 (5). pp. 2647-2657. ISSN 0556-2791
Andrews, David L. (1982) The theory of double-beam three-photon absorption. The Journal of Chemical Physics, 77 (6). pp. 2831-2835. ISSN 0021-9606