Lehmann, D. R., & Lehmann, D. R. (2002). Analysis for marketing planningDonald R. Lehmann, Russell S. Winer. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Lehmann, Donald R., agus Donald R. Lehmann. Analysis for Marketing PlanningDonald R. Lehmann, Russell S. Winer. McGraw-Hill, 2002.
Lua MLA (8ú heag.)Lehmann, Donald R., agus Donald R. Lehmann. Analysis for Marketing PlanningDonald R. Lehmann, Russell S. Winer. McGraw-Hill, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.