1. Fall speeds of precipitation elements.;Cornford;Q. J. R. Meteorol. Soc.,1965
2. Super-terminal raindrops.;Cornford;Weather,2009
3. Entrainment and its causes.;Gregory;Weather,2010
4. World of Molecules. 2010 Interactive molecules - ice structure. http://www.worldofmolecules.com/interactive_molecules/ice.htm