BPB Publications. (1990). Ingenuity Unlimited. BPB Publications.
Cita Chicago (17th ed.)BPB Publications. Ingenuity Unlimited. New Delhi: BPB Publications, 1990.
Cita MLA (9th ed.)BPB Publications. Ingenuity Unlimited. BPB Publications, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.