Παραπομπή σε μορφή APA (7η εκδ.)

Langdon-Dahm, M. (1986). Trade secrets: 25 proven success tools for working, dealing ... Learning development systems.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Langdon-Dahm, Martha. Trade Secrets: 25 Proven Success Tools for Working, Dealing ... Dayton: Learning development systems, 1986.

Παραπομπή σε μορφή MLA (9th εκδ.)

Langdon-Dahm, Martha. Trade Secrets: 25 Proven Success Tools for Working, Dealing ... Learning development systems, 1986.