Friedrich, K. (1974). International economics: Concepts and issues. McGraw- Hill.
Cita Chicago (17th ed.)Friedrich, Klaus. International Economics: Concepts and Issues. NewYork: McGraw- Hill, 1974.
Cita MLA (9th ed.)Friedrich, Klaus. International Economics: Concepts and Issues. McGraw- Hill, 1974.
Atenció: Aquestes cites poden no estar 100% correctes.