Cita APA (7a ed.)

CHRISTOPHERSEN, P. (1969). An advanced english grammar. Macmillan.

Cita Chicago Style (17a ed.)

CHRISTOPHERSEN, Paul. An Advanced English Grammar. London: Macmillan, 1969.

Cita MLA (9a ed.)

CHRISTOPHERSEN, Paul. An Advanced English Grammar. Macmillan, 1969.