Bird, S., Klein, E., & Loper, E. (2009). Natural language processing with Python (First edition.). O'Reilly.
Lua i Stíl Chicago (17ú heag.)Bird, Steven, Ewan Klein, agus Edward Loper. Natural Language Processing with Python. First edition. Beijing ; Cambridge, Mass.: O'Reilly, 2009.
Lua MLA (8ú heag.)Bird, Steven, et al. Natural Language Processing with Python. First edition. O'Reilly, 2009.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.