Cita APA

Koch, R. S., & Rachel Spack Koch; Keith S. Foles. (2006). Focus on grammar: An integrated skills approach. New York, NY: Pearson/Longman.

Citación estilo Chicago

Koch, Rachel Spack, y Rachel Spack Koch; Keith S. Foles. Focus On Grammar: An Integrated Skills Approach. New York, NY: Pearson/Longman, 2006.

Cita MLA

Koch, Rachel Spack, y Rachel Spack Koch; Keith S. Foles. Focus On Grammar: An Integrated Skills Approach. New York, NY: Pearson/Longman, 2006.