User:Yath/sandbox0

Textbooks using $\epsilon _{0}\$:

1. Edmonds, Dean S. Jr. Cioffari's Experiments in College Physics. New York: Houghton Mifflin, 1997. ISBN 0-669-41830-7

Textbooks using $\varepsilon _{0}$:

1. Halliday, David, Robert Resnick, and Jearl Walker. Fundamentals of Physics. 6th ed. New York: John Wiley & Sons, 2001. ISBN 0-471-32000-5
2. Wehr, Russell M., James A Richards, Jr., and Thomas W. Adair, III. Physics of the Atom. 4th ed. Reading, Mass.: Addison-Wesley, 1984. ISBN 0-201-08878-9

Websites using $\epsilon _{0}\$:

1. University of Pennsylvania
2. Wolfram Research
3. McGraw-Hill
4. University of Texas at Austin

Websites using $\varepsilon _{0}$:

1. Georgia State University Department of Physics and Astronomy
2. Plus 2 Physics
3. MATTER Initiative for Schools

Confused websites:

1. NIST

Potentially authoritative sources:

• permittivity of a vacuum at IUPAC Compendium of Chemical Terminology - $\varepsilon _{0}$