GILBREATH, R. D. (1987). Forward Thingking The Pragmatists Guide To Todays Business Trends Robert D. Gilbreath. Mcg-Hill.
Lua i Stíl Chicago (17ú heag.)GILBREATH, Robert D. Forward Thingking The Pragmatists Guide To Todays Business Trends Robert D. Gilbreath. Mcg-Hill, 1987.
Lua MLA (8ú heag.)GILBREATH, Robert D. Forward Thingking The Pragmatists Guide To Todays Business Trends Robert D. Gilbreath. Mcg-Hill, 1987.
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