APA aipamena

(1989). Practice and reinforcement: (Blue level). New York: Mc Dougal, Littell & Company.

Chicago Style aipamena

Practice and Reinforcement: (Blue Level). New York: Mc Dougal, Littell & Company, 1989.

MLA aipamena

Practice and Reinforcement: (Blue Level). New York: Mc Dougal, Littell & Company, 1989.