Drennan, D., & Pennington, S. (1999). 12 ladders to world class performance: How your organization can compete with the best in the world. Kogan Page.
Citazione stile Chigago Style (17a edizione)Drennan, David, e Stewart Pennington. 12 Ladders to World Class Performance: How Your Organization Can Compete with the Best in the World. London: Kogan Page, 1999.
Citatione MLA (9a ed.)Drennan, David, e Stewart Pennington. 12 Ladders to World Class Performance: How Your Organization Can Compete with the Best in the World. Kogan Page, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.