Air-Conditioning & Refrigeration Institute. Refrigeration and Air-Conditioning. 2nd Ed. Prentice-Hall Inc., 1987.

Elliot, Richard J. and Carl T. Lira. Introductory Chemical Engineering Thermodynamics. Prentice Hall PTR, 1999.

Sparks, Norman R. and Charles C. DiIlIo. Mechanical Refrigeration. 2nd Ed. New York: McGraw-Hill Book Company, Inc.,             1959.

1998 ASHRAE Handbook, Refrigeration. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.,             1998.

Old Refrigerator. http://shop.store.yahoo.com/americabilia-com/ligkeyhol.html.

New Refrigerator http://a1416.g.akamaitech.net/f/1416/281/12h/ccimg.catalogcity.com/190000/191000/191001/products/D1707W.jpg