Schultz, W. J., & Reinhardt, H. (1962). Credit and collection management (3rd ed.). Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Schultz, William John, agus Hedwig Reinhardt. Credit and Collection Management. 3rd ed. Englewood Cliffs, N. J: Prentice-Hall, 1962.
Lua MLA (9ú heag.)Schultz, William John, agus Hedwig Reinhardt. Credit and Collection Management. 3rd ed. Prentice-Hall, 1962.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.