APA (7th ed.) Citation

Frey, D. (1993). !%: : a directory of electronic mail addressing and networks (3. ed.). O'Reilly.

Chicago Style (17th ed.) Citation

Frey, Donnalyn. !%: : A Directory of Electronic Mail Addressing and Networks. 3. ed. Sebastopol, Calif: O'Reilly, 1993.

MLA (9th ed.) Citation

Frey, Donnalyn. !%: : A Directory of Electronic Mail Addressing and Networks. 3. ed. O'Reilly, 1993.