@book{compsci364,
           month = {July},
           title = {Word Frequencies in Written and Spoken English: based on the British National Corpus},
          author = {G. Leech and P. Rayson and A. Wilson},
         address = {London},
       publisher = {Longman},
            year = {2001},
             url = {http://eprints.comp.lancs.ac.uk/364/}
}