The primary sources for background information are websites, books, and journals and magazines that feature or focus on the phenomenon.
Websites
New Energy Foundation, with the Magazine, Infinite Energy
LENR-CANR.org (Website’s Name)
(More coming…)
Books
The Science of Low Energy Nuclear Reaction, Edmund Storms, 2007
The Explanation of Low Energy Nuclear Reaction, Edmund Storms, 2014
Excess Heat: Why Cold Fusion Research Prevailed (2nd Edition), Charles Beaudette, 2002
(More coming…)
Journals and Magazines
Infinite Energy (New Energy Foundation)
Journal of Condensed Matter Nuclear Science
(More coming…)