Chú thích Kỷ Permi

  1. ↑ Image:Sauerstoffgehalt-1000mj.svg
  2. ↑ Image:Phanerozoic Carbon Dioxide.png
  3. ↑ Image:All palaeotemps.png
  4. ↑ Haq, B. U.; Schutter, SR (2008). “A Chronology of Paleozoic Sea-Level Changes”. Science 322 (5898): 64–68. Bibcode:2008Sci...322...64H. PMID 18832639. doi:10.1126/science.1161648. 
  5. ↑ ICS (2012). “International Chronostratigraphic Chart”. 
  6. ↑ “Chart/Time Scale”. www.stratigraphy.org. International Commission on Stratigraphy. 
  7. ↑ Zimmerman EC (1948) Insects of Hawaii, Vol. II. Univ. Hawaii Press
  8. ↑ Riek EF Kukalova-Peck J (1984) A new interpretation of dragonfly wing venation based on early Upper Carboniferous fossils from Argentina (Insecta: Odonatoida and basic character states in Pterygote wings.) Can. J. Zool. 62; 1150-1160