@article{CTT100867889,
  author = {Jun-ichi Aihara and Tsuyoshi Horikawa},
  title = {Graph-theoretical formula for ring currents induced in a polycyclic conjugated system.},
  journal = {Bull. Chem. Soc. Jpn.},
  year = 1983,
}

@article{CTT100867887,
  author = {Tsuyoshi Horikawa and Jun-ichi Aihara},
  title = {Contribution of quadruply degenerate .PI.-electron orbitals to London susceptibility.},
  journal = {Bull. Chem. Soc. Jpn.},
  year = 1983,
}

@article{CTT100867888,
  author = {Jun-ichi Aihara and Tsuyoshi Horikawa},
  title = {General graph-theoritical formula for the London susceptibility of a cyclic conjugated system with highly degenerate orbitals},
  journal = {Chemical Physics Letters},
  year = 1983,
}