Dyfyniad APA
De Bono, E. (1999). Six thinking hats (1st Back Bay pbk. ed., rev. and updated.). Back Bay Books.
Dyfyniad Arddull Chicago
De Bono, Edward. Six Thinking Hats. 1st Back Bay pbk. ed., rev. and updated. Boston: Back Bay Books, 1999.
Dyfyniad MLA
De Bono, Edward. Six Thinking Hats. 1st Back Bay pbk. ed., rev. and updated. Back Bay Books, 1999.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.