Culpeper, Jonathan. English Language: Description, Variation and Context. Houndmills, Basingstoke: Palgrave Macmillan, 2009. Print.
---, eds. English Language: Description, Variation and Context. Second edition. London: Palgrave, 2018. Web. <http://www.vlebooks.com/vleweb/product/openreader?id=LeicesterU&isbn=9781137571854>.
Merrison, Andrew et al. Introducing Language in Use: A Coursebook. Second Edition. London: Routledge, Taylor & Francis Group, 2014. Print.
Merrison, Andrew John et al. Introducing Language in Use: A Course Book. 2nd ed. Florence: Taylor and Francis, 2013. Web. <http://ebookcentral.proquest.com/lib/leicester/detail.action?docID=1582671>.
