It's available from archive.org via a 1 hour loan: https://archive.org/details/methodsofinforma0000unse .
It's sad that there's no real competition in online search anymore.
bash and the Bourne shell aren't the same thing. More or less, this is the history:
* in 1979, sh (Bourne SHell), created by Stephen Bourne, is released as part of AT&T Unix
* in 1983, ksh (Korn SHell), created by David Korn, an enhanced version of sh, is released by AT&T
* in 1989, bash (Bourne Again SHell), created by Brian Fox, is an open-source alternative released by the GNU project