APA (7th ed.) Citation

Ludlum, R. (2002). The Sigma protocol (St. Martin's pbk. ed.). St. Martin's Paperbacks.

Chicago Style (17th ed.) Citation

Ludlum, Robert. The Sigma Protocol. St. Martin's pbk. ed. New York: St. Martin's Paperbacks, 2002.

MLA (8th ed.) Citation

Ludlum, Robert. The Sigma Protocol. St. Martin's pbk. ed. St. Martin's Paperbacks, 2002.

Warning: These citations may not always be 100% accurate.