Gaya APA

Walter, C. et al (1998). The New cambridge English course : upper-intermediate practice 4 + key / Desmond O'Sullivan, Michael Swan, Catherine Walter (Cet.5). New York: .

Gaya MLA

Walter, Catherine. et al. "The New cambridge English course : upper-intermediate practice 4 + key / Desmond O'Sullivan, Michael Swan, Catherine Walter". Cet.5 New York: , 1998. Textbook.