Bird, S., Klein, E., & Loper, E. (2009). Natural language processing with Python (First edition.). O'Reilly.
Citazione stile Chigago Style (17a edizione)Bird, Steven, Ewan Klein, e Edward Loper. Natural Language Processing with Python. First edition. Beijing ; Cambridge, Mass.: O'Reilly, 2009.
Citatione MLA (8a ed.)Bird, Steven, et al. Natural Language Processing with Python. First edition. O'Reilly, 2009.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.