Cita APA (7a ed.)
Allen, J., & Widdowson, H. (1974). English in Focus. English in Physical Science (Teacher's Edition.). Oxford University Press.
Cita Chicago Style (17a ed.)
Allen, J.P.B, y H.G Widdowson. English in Focus. English in Physical Science. Teacher's Edition. Oxford: Oxford University Press, 1974.
Cita MLA (9a ed.)
Allen, J.P.B, y H.G Widdowson. English in Focus. English in Physical Science. Teacher's Edition. Oxford University Press, 1974.
Precaución: Estas citas no son 100% exactas.