Alexander, L. (1991). New Concept English: First Things First. London: Longman.
Dyfyniad Arddull ChicagoAlexander, L.g. New Concept English: First Things First. London: Longman, 1991.
Dyfyniad MLAAlexander, L.g. New Concept English: First Things First. London: Longman, 1991.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.