Cita APA

Roberts, P. D. (1987). Plan English a user's guide. USA: Penguin Books.

Chicago Style Citation

Roberts, Philip Davies. Plan English a User's Guide. USA: Penguin Books, 1987.

Cita MLA

Roberts, Philip Davies. Plan English a User's Guide. USA: Penguin Books, 1987.

Atenció: Aquestes cites poden no estar 100% correctes.