قالب انواع نامه ها
http://writinghelp-central.com/sample-letters.html
http://writinghelp-central.com/letter-formats.html
اصول نامه نگاری
http://www.wendy.com/letterwriting/
http://www.career.fsu.edu/ccis/guides/write_eff.html
http://www.libraryonline.com/
http://esl.about.com/cs/onthejobenglish/a/a_basbletter.htm