http://www.hb.se/bib/harvard/har.asp
http://www.ida.his.se/ida/exjobb/referenser.pdfYou can also have a look at these pages:
http://school.discovery.com/schrockguide/
(Teacher helpers + Critical Evaluation tools)
List of frequently misused English words
http://en.wikipedia.org/wiki/List_of_English_words_with_frequent_misuse
List of common misspellings in English
http://en.wikipedia.org/wiki/List_of_common_misspellings_in_English
List of commonly confused homonyms
http://en.wikipedia.org/wiki/List_of_commonly_confused_homonyms
Spelling Center
http://www.spellingcenter.com/