توثيق جمعية علم النفس الأمريكية APA (الطبعة السابعة)

Perkins, J. (2010). Python text processing with NLTK 2.0 cookbook: Over 80 practical recipes for using Python's NLTK suite of libraries to maximize your natural language processing capabilities. Packt Pub..

توثيق أسلوب شيكاغو (الطبعة السابعة عشر)

Perkins, Jacob. Python Text Processing with NLTK 2.0 Cookbook: Over 80 Practical Recipes for Using Python's NLTK Suite of Libraries to Maximize Your Natural Language Processing Capabilities. Birmingham, U.K.: Packt Pub., 2010.

توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)

Perkins, Jacob. Python Text Processing with NLTK 2.0 Cookbook: Over 80 Practical Recipes for Using Python's NLTK Suite of Libraries to Maximize Your Natural Language Processing Capabilities. Packt Pub., 2010.