recommended book/guide for /bin/sh shell programming

[Dave [Hawk-Systems]]

For multiple reasons I am moving away from doing everything in perl/php for
server based tasks. Made sense at the time to do everything in the language we
used for the web as well, but am finding I do less web work and more server
admin work as time progreses, and there are some significant hits to loading
perl or php each time I want to move files and do other such tasks. As such I am
finding more and more tasks being performed in plain ol shell scripting, thousgh
this is still a hunt and peck type of operation fr the appropriate commands
etc...

As such, am looking for recommendations for a good guide/book or two for shell
programming, but most of the books seem to be specific to bash, tcsh, ksh,
etc... Given that there is a seperate bash shell port available, I would assume
that /bin/sh != bash.  I would prefer to use plain ol /bin/sh since most of the
core scripts scattered through the stable installs we have use it.

Sugestions? Amazon links?

Thanks

Dave