DeGarmo, E. P., Canada, J. R., & Sullivan, W. G. (1979). Engineering economy (6th ed.). Macmillan.
Lua i Stíl Chicago (17ú heag.)DeGarmo, E. Paul, John R. Canada, agus William G. Sullivan. Engineering Economy. 6th ed. New York: Macmillan, 1979.
Lua MLA (9ú heag.)DeGarmo, E. Paul, et al. Engineering Economy. 6th ed. Macmillan, 1979.
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