Dark Space Universe by Jasper T. Scott Page 26
[14] If the Universe is Flat, has Finite Mass/Energy, and is Simply Connected, Then there MUST be an Edge, Mustn’t there? http://physics.stackexchange.com/questions/311468/if-the-universe-is-flat-has-finite-mass-energy-and-is-simply-connected-then-t
[15] We Probably Haven’t Found Evidence for the Multiverse http://gizmodo.com/we-probably-havent-found-evidence-for-the-multiverse-1740611389
[16] Doughnut-shaped Universe bites back http://www.nature.com/news/2008/080523/full/news.2008.854.html
[17] The Status of Cosmic Topology after Planck Data https://arxiv.org/ftp/arxiv/papers/1601/1601.03884.pdf
