Author E. Landing A.W.A. Rushton R.A. Fortey S.A. Bowring Landing, E., Rushton, A.W.A., Fortey, R.A., Bowring, S.A., 2015. Improved Geochronologic Accuracy and Precision for the ICS Chronostratigraphic Charts: Examples from the late Cambrian–Early Ordovician. Episodes 38, 154-161.