This page presents a number of links related to the Three Phase ISM tool.
Wikipedia. This web article gives a general introduction to the interstellar medium.
Planetary Science Research Discoveries. This web site provides a large number of informative articles on recent insights into planetary science. Some articles particularly relevant for radioactivities and the three phase ISM tool are:
ABCs of Nuclear Science. This web article presents some of the basics of nuclear science and radioactivity.
