==Eksterne henvisninger==
* [http://www.periodicvideos.com/videos/089.htm Actinium] i ''[[The Periodic Table of Videos]]'' (University of Nottingham)
* [http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@na+@rel+actinium,+radioactive NLM Hazardous Substances Databank – Actinium, Radioactive]
* [https://web.archive.org/web/20110825123745/http://radchem.nevada.edu/classes/rdch710/files/actinium.pdf Actinium] i {{cite book
| title = The Chemistry of the Actinide and Transactinide Elements
| editor1-last = Morss |editor2-first = Norman M.
| editor2-last = Edelstein
| editor3-last = Fuger |editor3-first = Jean
| last1 = Kirby |first1 = H. W.
| last2 = Morss |first2 = L. R.
| publisher = Springer
| date = 2006
| isbn = 978-1-4020-3555-5
| location = Dordrecht, The Netherlands
| edition = 3rd
}}
Kemi