Citazione Stile APA (7a Edizione)

Vallen, G. K., Vallen, J. J., & Robinson, G. F. (2008). Check-in check-out (2nd Canadian ed.). Pearson Education.

Citazione stile Chigago Style (17a edizione)

Vallen, Gary K., Jerome J. Vallen, e Gary F. Robinson. Check-in Check-out. 2nd Canadian ed. Toronto, Ontario: Pearson Education, 2008.

Citatione MLA (9a ed.)

Vallen, Gary K., et al. Check-in Check-out. 2nd Canadian ed. Pearson Education, 2008.