TY  - RPRT
TI  - Defining the Devonian: 1979-89
AU  - W. A. Oliver
AU  - I. Chlupac
PY  - 1991
DO  - 10.1111/j.1502-3931.1991.tb01185.x
UR  - https://pubs.usgs.gov/publication/70016613
ID  - 70016613
ER  -