Cita APA (7th ed.)

(1977). Building English skills: Orange level. McDougal, Littell & Company.

Cita Chicago (17th ed.)

Building English Skills: Orange Level. Evanston, Illinois, USA: McDougal, Littell & Company, 1977.

Cita MLA (9th ed.)

Building English Skills: Orange Level. McDougal, Littell & Company, 1977.