Öpik, A. A. (1970). Nepeid trilobites of the Middle Cambrian of northern Australia. Bureau of Mineral Resources, Geology and Geophysics.
Dyfyniad Arddull ChicagoÖpik, A. A. Nepeid Trilobites of the Middle Cambrian of Northern Australia. Canberra: Bureau of Mineral Resources, Geology and Geophysics, 1970.
Dyfyniad MLAÖpik, A. A. Nepeid Trilobites of the Middle Cambrian of Northern Australia. Bureau of Mineral Resources, Geology and Geophysics, 1970.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.