Kolby, J. &. o. (2015). GMAT: DATA Sufficiency Prep Course. Prakash Pub.
Dyfyniad Arddull ChicagoKolby, Jeff & others. GMAT: DATA Sufficiency Prep Course. New Delhi: Prakash Pub, 2015.
Dyfyniad MLAKolby, Jeff & others. GMAT: DATA Sufficiency Prep Course. Prakash Pub, 2015.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.