[4] He was the first author to use the term "Eastern Europeans" in a book title, in his Untersuchungen über die Geschichte der östlichen europäischen Völker, 1774.
[9] Thunmann was one of the most important early authors writing about the language and origin of Albanians.
[10] The first serious attempts to present scientific explanation of the origin of Albanians began with Thunmann.
[11] He believed that in terms of history and language, the Albanians and the Aromanians were the least known European peoples in Western Europe.
[16] In 1774 Thunmann republished a three-language (Albanian, Greek and Aromanian) lexicon Theodor Kavalioti first published in 1770, and later added a Latin translation.