HOLTJE, H. F. (1981). Schaum's Outline Of Theory And Problems Of Marketing Hebert F. Holtje. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)HOLTJE, Herbert. F. Schaum's Outline Of Theory And Problems Of Marketing Hebert F. Holtje. McGraw-Hill, 1981.
Lua MLA (8ú heag.)HOLTJE, Herbert. F. Schaum's Outline Of Theory And Problems Of Marketing Hebert F. Holtje. McGraw-Hill, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.