In trying to find an explanation for a certain phenomenon, I decided to compare the frequencies of letters in a certain group of words with some norm. I was not too happy with available lists because of their small sample size, and also because it was difficult to see whether differences in rank between different lists were significant. Therefore I made my own. The table in the article is compiled from approximately 7 million letters in my large 'dictionary' (compared with, for example, the 10 thousand letters of running text, not dictionary words, of Helen Gaines in Cryptanalysis).
"Letter Frequencies and Word Lengths,"
Word Ways: Vol. 30
, Article 5.
Available at: http://digitalcommons.butler.edu/wordways/vol30/iss2/5