RIES AL. (1996). FOCUS: THE FUTURE OF YOUR COMPANY DEPENDS UPON IT. HARPER COLLINS PUBLISHERS.
Chicago Style aipamenaRIES AL. FOCUS: THE FUTURE OF YOUR COMPANY DEPENDS UPON IT. USA: HARPER COLLINS PUBLISHERS, 1996.
MLA aipamenaRIES AL. FOCUS: THE FUTURE OF YOUR COMPANY DEPENDS UPON IT. HARPER COLLINS PUBLISHERS, 1996.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.