Challenges in defining the base of Cambrian Series 2 and Stage 3

1. Zhang, X.
2. Ahlberg, P.
3. Babcock, L.E.
4. Choi, D.K.
5. Geyer, G.
6. Gozalo, R.
7. Stewart Hollingsworth, J.
8. Li, G.
9. Naimark, E.B.
10. Pegel, T.
11. Steiner, M.
12. Wotte, T.
13. Zhang, Z.