O'brien, B. (2011). Concise general knowledge manual 2012. Cengage Learning.
Chicago Edition CitationO'brien, Barry. Concise General Knowledge Manual 2012. New Delhi: Cengage Learning, 2011.
MLA Edition CitationO'brien, Barry. Concise General Knowledge Manual 2012. Cengage Learning, 2011.
Warning: These citations may not always be 100% accurate.