Percil, J., & Gray, J. (1988). Prospects: An advanced course teacher's book. Penguin Books.
Chicagoスタイル(17版)引用形式Percil, John, , Joanna Gray. Prospects: An Advanced Course Teacher's Book. London: Penguin Books, 1988.
MLA(9版)引用形式Percil, John, , Joanna Gray. Prospects: An Advanced Course Teacher's Book. Penguin Books, 1988.
警告: この引用は必ずしも正確ではありません.