APA (7e ed.) Bronvermelding

KIMBROUGH, V. F., & VAI, M. (1991). English on call level one. McGraw-hill.

Chicago (17e ed.) Bronvermelding

KIMBROUGH, Victoria F., en Marjorie VAI. English on Call Level One. New York: McGraw-hill, 1991.

MLA (9e ed.) Bronvermelding

KIMBROUGH, Victoria F., en Marjorie VAI. English on Call Level One. McGraw-hill, 1991.