↑"Hydrogen". Van Nostrand's Encyclopedia of Chemistry. Wylie-Interscience. 2005. pp. 797–799. ISBN0-471-61525-0.{{cite ensiklopedya}}: CS1 maint: date auto-translated (link)
↑Emsley, John (2001). Nature's Building Blocks. Oxford: Oxford University Press. pp. 183–191. ISBN0-19-850341-5.{{cite book}}: CS1 maint: date auto-translated (link)
↑Stwertka, Albert (1996). A Guide to the Elements. Oxford University Press. pp. 16–21. ISBN0-19-508083-1.{{cite book}}: CS1 maint: date auto-translated (link)