Litwin, R.J., and Ash, S.R., 1991, First early Mesozoic amber in the western hemisphere: Geology, v. 19, no. 3, p. 273-276.
Litwin, R.J., and Ash, S.R.
Geology, v. 19, no. 3, p. 273-276.
Paleontology, Fossil Plant, Locale, Petrified Forest Mbr - Chinle Fm - Triassic,