Slappey, S. G. (1973). Pioneers of American business: Comp. by Sterling G. Slappey (2. print.). Grosset & Dunlap.
Lua i Stíl Chicago (17ú heag.)Slappey, Sterling G. Pioneers of American Business: Comp. by Sterling G. Slappey. 2. print. New York [u.a.]: Grosset & Dunlap, 1973.
Lua MLA (8ú heag.)Slappey, Sterling G. Pioneers of American Business: Comp. by Sterling G. Slappey. 2. print. Grosset & Dunlap, 1973.
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