Singleton, D., & Ryan, L. (2004). Language acquisition: The age factor (2nd ed.). Multilingual Matters Ltd..
芝加哥风格引文Singleton, David, 与 Lisa Ryan. Language Acquisition: The Age Factor. 2nd ed. Clevedon: Multilingual Matters Ltd., 2004.
MLA引文Singleton, David, 与 Lisa Ryan. Language Acquisition: The Age Factor. 2nd ed. Multilingual Matters Ltd., 2004.
警告：这些引文格式不一定是100％准确.