These were used for background information:

Fluid Characteristics Chart / Data, Density, Vapor Pressure and Viscosity.  Engeneers Edge.  May 7, 2004.  <http://www.engineersedge.com/fluid_flow/fluid_data.htm>

LaChapelle, Edward R.  Field Guide to Snow Crystals.  Vancouver: J. J. Douglas Ltd., 1969.

Safety (MSDS) data for acetic acid.  March 2004. May 7, 2004.   <http://ptcl.chem.ox.ac.uk/MSDS/AC/acetic_acid.html>

Safety (MSDS) data for glycerol.  September 2003. May 7, 2004.   <http://ptcl.chem.ox.ac.uk/MSDS/GL/glycerol.html>

Seligman, G. Snow Structure and Ski Fields.  Brussels, Belgium: Jos. Adams, 1962.

Snowflakes and Snow Crystals. February 1999.   Kenneth Libbrecht.  May 7, 2004. <http://www.its.caltech.edu/~atomic/snowcrystals>