Heliumdokumentasjon
U.S. Geological Survey, Mineral Commodity Summaries, January 2018
Heliumdokumentasjon for flere år: https://minerals.usgs.gov/minerals/pubs/commodity/helium/
Artikkel i Daily Mail: Om stort funn av helium i Tanzania.
Artikkel Geological Society in London «Helium – Hero or Houdini?»
Artikkel i Forbes «We’re really not about to run out of helium…»
Mass Latex Balloon Releases and the Potential Effects on Wildlife
Stephan Irwin – Clemson Uni – 2012
Inhaling Helium Can Be Deadly
Medscape – Deborah Brauser – 2012
Origins, transport and accumulation of Helium
The Geological Society
Species Profile – Rubber Tree
Rainforest Alliance
