Παραπομπή APA

Koch, R. S., & Rachel Spack Koch. (1997). Focus on Grammar An Course for Reference and Practice. Tp. Hồ Chí Minh: Nxb. Tp. Hồ Chí Minh.

Παραπομπή Chicago Style

Koch, Rachel Spack, και Rachel Spack Koch. Focus On Grammar An Course for Reference and Practice. Tp. Hồ Chí Minh: Nxb. Tp. Hồ Chí Minh, 1997.

Παραπομπή MLA

Koch, Rachel Spack, και Rachel Spack Koch. Focus On Grammar An Course for Reference and Practice. Tp. Hồ Chí Minh: Nxb. Tp. Hồ Chí Minh, 1997.

Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.