APA সাইটেশন

(1987). Practice and reinforcement: (Purple level). New York: McDougal, Littell & Companay.

শিকাগো স্টাইলে সাইটেশন

Practice and Reinforcement: (Purple Level). New York: McDougal, Littell & Companay, 1987.

এমএলএ সাইটেশন

Practice and Reinforcement: (Purple Level). New York: McDougal, Littell & Companay, 1987.