https://io9.gizmodo.com/5382576/5382576/5382576/how-many-universes-exist-in-the-multiverse-physicists-may-have-a-number
https://arxiv.org/abs/0910.1589
https://books.google.com/books?id=kQRPkTkk_VIC&printsec=frontcover&dq=dictionary+of+interesting+numbers&hl=en&ei=jsDkTefIJdPciALf86TXCQ&sa=X&oi=book_result&ct=result#v=onepage&q&f=false