APA (7th ed.) Citation

(2009). Information retrieval: Searching in the 21st century. Wiley.

Chicago Style (17th ed.) Citation

Information Retrieval: Searching in the 21st Century. Chichester, U.K: Wiley, 2009.

MLA (9th ed.) Citation

Information Retrieval: Searching in the 21st Century. Wiley, 2009.

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