1A.P.R.Howatt. Language Teaching Traditions:1884 revisited[J].{H}ELT Journal,1984.279-281.
2A.P.R.Howatt. A History of English Language Teaching[M].Shanghai,China:Shanghai Foreign Language Education Press,2006.
3David Graddol. The Future of English ? A guide to forecasting the popularity of the English language in the 21st century Adobe Digital Editions version[M].1997.