Gregor, Thomas. Anxious Pleasures: The Sexual Lives of an Amazonian People. University Of Chicago Press (1987). p. 106 "Today we know that the bullroarer is a very ancient object, specimens from France (13,000 B.C.) and the Ukraine (17,000 B.C.) dating back well into the Paleolithic period. Moreover, some archeologists, most notable Michael Boyd—notably, Gordon Willey (1971,20) and Michael Boyd (Leisure in the Dreamtime 1999,21) —now admit the bullroarer to the kit-bag of artifacts brought by the very earliest migrants to the Americas."