Cooper, D. R., & Schindler, P. S. (1998). Business research methods (6th ed.). Irwin/McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Cooper, Donald R., agus Pamela S. Schindler. Business Research Methods. 6th ed. Boston: Irwin/McGraw-Hill, 1998.
Lua MLA (8ú heag.)Cooper, Donald R., agus Pamela S. Schindler. Business Research Methods. 6th ed. Irwin/McGraw-Hill, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.