Gaya APA

Koch, R, S., Folse, W, K, S. (2006). Focus on grammar – an integrated skills approach (Ed. 3). USA: Pearson longman.

Gaya MLA

Koch, Rachel, Spack., Folse, With, Keith, S. "Focus on grammar – an integrated skills approach". Ed. 3 USA: Pearson longman, 2006. Umum.