Information Loss in Black Holes and/or Conscious Beings?, Don N. Page, Heat Kernel Techniques and Quantum Gravity (1995), S. A. Fulling (ed), p. 461. Discourses in Mathematics and its Applications, No. 4, Texas A&M University Department of Mathematics. arXiv:hep-th/9411193. ISBN 0-9630728-3-8.
Kasner, Edward; Newman, James R.Mathematics and the Imagination (англ.). — Simon and Schuster, New York, 1940. — ISBN 0-486-41703-4. The relevant passage about the googol and googolplex, attributing both of these names to Kasner’s nine-year-old nephew, is available in The world of mathematics, volume 3 (англ.) / James R. Newman. — Mineola, New York: Dover Publications, 2000. — P. 2007—2010. — ISBN 978-0-486-41151-4.