Gaya APA

TOEFL, T, O, G, T, T. (2012). The Official Guide to the TOEFL Test 4th ed (4). New York: McGraw Hill.

Gaya MLA

TOEFL, The, Official, Guide, To, The. "The Official Guide to the TOEFL Test 4th ed". 4 New York: McGraw Hill, 2012. Printed.