Kingsbury, R. y. (1996). Grammar Plus 2 (1a. ed.). Longman.
Cita Chicago Style (17a ed.)Kingsbury, Roy y. Grammar Plus 2. 1a. ed. Londres: Longman, 1996.
Cita MLA (9a ed.)Kingsbury, Roy y. Grammar Plus 2. 1a. ed. Longman, 1996.
警告:這些引文格式不一定是100%准確.