Lu, Limin; Sargent, Wallace L. W.; Barlow, Thomas A.; et al. (13 February 1998). "The Metal Contents of Very Low Column Density Lyman-alpha Clouds: Implications for the Origin of Heavy Elements in the Intergalactic Medium". arXiv:astro-ph/9802189.
Overbye, Dennis (17 March 2014). "Space Ripples Reveal Big Bang's Smoking Gun". Space & Cosmos. The New York Times. ISSN0362-4331. Archived from the original on 17 March 2014. Retrieved 6 January 2020. "A version of this article appears in print on March 18, 2014, Section A, Page 1 of the New York edition with the headline: Space Ripples Reveal Big Bang’s Smoking Gun." The online version of this article was originally titled "Detection of Waves in Space Buttresses Landmark Theory of Big Bang".
Overbye, Dennis (17 March 2014). "Space Ripples Reveal Big Bang's Smoking Gun". Space & Cosmos. The New York Times. ISSN0362-4331. Archived from the original on 17 March 2014. Retrieved 6 January 2020. "A version of this article appears in print on March 18, 2014, Section A, Page 1 of the New York edition with the headline: Space Ripples Reveal Big Bang’s Smoking Gun." The online version of this article was originally titled "Detection of Waves in Space Buttresses Landmark Theory of Big Bang".
Overbye, Dennis (17 March 2014). "Space Ripples Reveal Big Bang's Smoking Gun". Space & Cosmos. The New York Times. ISSN0362-4331. Archived from the original on 17 March 2014. Retrieved 6 January 2020. "A version of this article appears in print on March 18, 2014, Section A, Page 1 of the New York edition with the headline: Space Ripples Reveal Big Bang’s Smoking Gun." The online version of this article was originally titled "Detection of Waves in Space Buttresses Landmark Theory of Big Bang".