Cita APA (7a ed.)

Schoenberg, I. E., & Maurer, J. (2006). Focus on Grammar 1: An integrated skills approach (Second edition.). Pearson Longman.

Cita Chicago Style (17a ed.)

Schoenberg, Irene E., y Jay Maurer. Focus on Grammar 1: An Integrated Skills Approach. Second edition. United State: Pearson Longman, 2006.

Cita MLA (9a ed.)

Schoenberg, Irene E., y Jay Maurer. Focus on Grammar 1: An Integrated Skills Approach. Second edition. Pearson Longman, 2006.