Kolby, J. &. o. (2015). GMAT: DATA Sufficiency Prep Course. Prakash Pub.
芝加哥风格引文Kolby, Jeff & others. GMAT: DATA Sufficiency Prep Course. New Delhi: Prakash Pub, 2015.
MLA引文Kolby, Jeff & others. GMAT: DATA Sufficiency Prep Course. Prakash Pub, 2015.
警告：这些引文格式不一定是100％准确.