Cita APA (7th ed.)

Kolby, J. &. o. (2015). GMAT: DATA Sufficiency Prep Course. Prakash Pub.

Cita Chicago (17th ed.)

Kolby, Jeff & others. GMAT: DATA Sufficiency Prep Course. New Delhi: Prakash Pub, 2015.

Cita MLA (9th ed.)

Kolby, Jeff & others. GMAT: DATA Sufficiency Prep Course. Prakash Pub, 2015.