Perry, John (1895) "On the age of the earth," Nature, 51 : 224-227Archive.is的存檔，存档日期2015-02-17, 341-342, 582-585. (51:224, 51:341, 51:582 at Internet Archive)
The life of William Thomson, baron Kelvin of Largs, vol2, "Views and Opinions"
Perry, John (1895) "On the age of the earth," Nature, 51 : 224-227Archive.is的存檔，存档日期2015-02-17, 341-342, 582-585. (51:224, 51:341, 51:582 at Internet Archive)
"Lord Kelvin, Nineteenth Century Clouds over the Dynamical Theory of Heat and Light", reproduced in Notices of the Proceedings at the Meetings of the Members of the Royal Institution of Great Britain with Abstracts of the Discourses, Volume 16, p. 363–397 （页面存档备份，存于互联网档案馆）
Kelvin did pay off gentleman's bet with Strutt on the importance of radioactivity in the Earth. The Kelvin period does exist in the evolution of stars. They shine from gravitational energy for a while (correctly calculated by Kelvin) before fusion and the main sequence begins. Fusion was not understood until well after Kelvin's time。参考文献：England, P.; Molnar, P.; Righter, F. John Perry's neglected critique of Kelvin's age for the Earth: A missed opportunity in geodynamics. GSA Today. January 2007, 17 (1): 4–9. doi:10.1130/GSAT01701A.1.
Thomson, W. (1851) "On the dynamical theory of heat; with numerical results deduced from Mr. Joule's equivalent of a thermal unit and M. Regnault's observations on steam" Math. and Phys. Papers vol. 1 （页面存档备份，存于互联网档案馆）, pp 175–183
Perry, John (1895) "On the age of the earth," Nature, 51 : 224-227Archive.is的存檔，存档日期2015-02-17, 341-342, 582-585. (51:224, 51:341, 51:582 at Internet Archive)
Thomson, W. (1851) "On the dynamical theory of heat; with numerical results deduced from Mr. Joule's equivalent of a thermal unit and M. Regnault's observations on steam" Math. and Phys. Papers vol. 1 （页面存档备份，存于互联网档案馆）, pp 175–183
"Lord Kelvin, Nineteenth Century Clouds over the Dynamical Theory of Heat and Light", reproduced in Notices of the Proceedings at the Meetings of the Members of the Royal Institution of Great Britain with Abstracts of the Discourses, Volume 16, p. 363–397 （页面存档备份，存于互联网档案馆）
