Aubry, M., Piller, W. E., Gibbard, P. L., Harper, D. A., & Finney, S. C. (2022). Ratification of subseries/subepochs as formal rank/units in international chronostratigraphy. Episodes, 45(1), 97-99. https://doi.org/10.18814/epiiugs/2021/021016