Author C. Isachsen S. Bowring E. Landing S. Samson Isachsen, C., Bowring, S., Landing, E., Samson, S., 1994. New Constraint on the Division of Cambrian Time. Geology 22, 496-498. doi:10.1130/0091-7613(1994)022<0496:NCOTDO>2.3.CO;2