Vallen, J. J. (1985). Check in check out: Principles of effective front office management (3rd ed.). Wm.C. Brown.
Cita Chicago (17th ed.)Vallen, Jerome J. Check in Check Out: Principles of Effective Front Office Management. 3rd ed. Dubuque, Iowa: Wm.C. Brown, 1985.
Cita MLA (9th ed.)Vallen, Jerome J. Check in Check Out: Principles of Effective Front Office Management. 3rd ed. Wm.C. Brown, 1985.
Atenció: Aquestes cites poden no estar 100% correctes.