In "Alfalfa and All That" in the November 1978 Word Ways, Leroy F. Meyers presented a variety of English and foreign words containing unhyphenated internal tautonyms. This article extends his work by classifying internal tautonyms in two ways -- by the repetition period, and by the length of the tautonymic part.
Eckler, A. Ross
Word Ways: Vol. 13
, Article 13.
Available at: http://digitalcommons.butler.edu/wordways/vol13/iss1/13