Cita APA (7th ed.)
Bird, S., Klein, E., & Loper, E. (2009). Natural Language Processing with Python. O'Reilly.
Cita Chicago (17th ed.)
Bird, Steven, Ewan Klein, i Edward Loper. Natural Language Processing with Python. Sebastopol, EUA: O'Reilly, 2009.
Cita MLA (9th ed.)
Bird, Steven, et al. Natural Language Processing with Python. O'Reilly, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.