Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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