text: * Chemical Bonding and Molecular Geometry: From Lewis to Electron Densities (Topics in Inorganic Chemistry) by Ronald J. Gillespie and Paul L. A. Popelier
  * Atoms, Molecules and Reactions: An Introduction to Chemistry by Ronald J. Gillespie
  * Chemistry by Ronald J. Gillespie, David Humphreys, Colin Baird, and E. A. Robinson
  * Atoms, Molecules and Reactions: An Introduction to Chemistry with D.A. Humphreys, E.A. Robinson and D.R. Eaton, Prentice Hall, 1994