United States. Information Agency, Voice of America (Organization), & Heald, H. T. (1970). The world of the engineer. Voice of America, United States Information Agency.
Παραπομπή σε μορφή Chicago (17η εκδ.)United States. Information Agency, Voice of America (Organization), και Henry T. Heald. The World of the Engineer. Washington, D.C.: Voice of America, United States Information Agency, 1970.
Παραπομπή σε μορφή MLA (8th εκδ.)United States. Information Agency, et al. The World of the Engineer. Voice of America, United States Information Agency, 1970.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.