Ur, P. Discussions that work: Task-centred fluency practice (1a ed., 8a reimpresión.).
芝加哥风格引文Ur, Penny. Discussions That Work: Task-centred Fluency Practice. 1a ed., 8a reimpresión.
MLA引文Ur, Penny. Discussions That Work: Task-centred Fluency Practice. 1a ed., 8a reimpresión.
警告：这些引文格式不一定是100％准确.