Institute For Scientific Co-operation. (1980). Economics. Laupp & Gobel, Tubingen.
Cita Chicago (17th ed.)Institute For Scientific Co-operation. Economics. Federal Republic of Germany: Laupp & Gobel, Tubingen, 1980.
Cita MLA (9th ed.)Institute For Scientific Co-operation. Economics. Laupp & Gobel, Tubingen, 1980.
Atenció: Aquestes cites poden no estar 100% correctes.