Tham khảo Tầng_Drum

  1. ↑ “ICS Timescale Chart”. www.stratigraphy.org.
  • Loren E. Babcock, Richard A. Robison, Margaret N. Rees, Shanchi Peng và Matthew R. Saltzman: The Global boundary Stratotype Section and Point (GSSP) of the Drumian stage (Cambrian) in the Drum Mountains, Utah, USA. Episodes. 30(2): 102-109, Bắc Kinh 2007 ISSN 0705-3797.
  • Felix Gradstein, Jim Ogg và Alan Smith: A Geologic timescale. Nhà in Đại học Cambridge, 2004 ISBN 9780521786737.

Tài liệu tham khảo

WikiPedia: Tầng_Drum http://palstrat.uni-graz.at/Stratigraphische_Tabel... http://www.gfz-potsdam.de/pb3/pb33/highlights/down... http://norges.uio.no/timescale/Fig11.2_Ord-colA.pd... http://www.stratigraphy.org/ http://www.stratigraphy.org/geowhen/index.html http://www.stratigraphy.org/index.php/ics-chart-ti... //tools.wmflabs.org/geohack/geohack.php?language=v... //www.worldcat.org/search?fq=x0:jrnl&q=n2:0705-379... https://web.archive.org/web/20060518101304/http://...