D. E.  Hardy and Knowlton, G. F., ?New and little known Utah Pipunculidae (Diptera)?, The Canadian Entomologist, vol. 71, pp. 87-91, 1939.

G. F.  Knowlton, ?The beet leafhopper in northern Utah?, Bull Utah agric. Exp. Sta. Bull., vol. 234, pp. 1-64, 1932.

G. F.  Knowlton, ?Notes on injurious Utah insects?, Proc. Utah Acad. Sci., vol. 10, pp. 153, 159-162, 1933.

G. F.  Knowlton and Janes, M. J., ?Notes on some beneficial Utah Diptera?, Rev. App. Ent. Ser. A, vol. 19, p. 629, 1931.