Freiberg, K. (2004). Guts: Companies that blow the doors off business as usual. Currency.
Chicago-viite (17. p.)Freiberg, Kevin. Guts: Companies That Blow the Doors off Business as Usual. New york: Currency, 2004.
MLA-viite (9. p.)Freiberg, Kevin. Guts: Companies That Blow the Doors off Business as Usual. Currency, 2004.
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