Lougheed, L. Barron's ielts: International language testing system.
Cita Chicago (17th ed.)Lougheed, Lin. Barron's Ielts: International Language Testing System. New Delhi New Age International 2007:.
Cita MLA (9th ed.)Lougheed, Lin. Barron's Ielts: International Language Testing System.
Atenció: Aquestes cites poden no estar 100% correctes.