Key points are not available for this paper at this time.
G. Evelyn Hutchinson, Enrico Bonatti, Ursula M. Cowgill, Clyde E. Goulden, Elaine A. Leventhal, M. E. Mallett, Fiorenza Margaritora, Ruth Patrick, A. Racek, Selwyn A. Roback, Emilia Stella, J. B. Ward-Perkins, Thomas R. Wellman, Ianula: An Account of the History and Development of the Lago di Monterosi, Latium, Italy, Transactions of the American Philosophical Society, Vol. 60, No. 4 (1970), pp. 1-178
Hutchinson et al. (Thu,) studied this question.