Dear Researcher, please note that what I am looking for is a QUOTATION
FROM A PUBLISHED TEXTBOOK, ALONG WITH DETAILS OF AUTHOR, TITLE,
PUBLISHER AND YEAR OF THE TEXTBOOK, with the answer to the following
question:

The program SAFE is manufactured by CSI Berkeley (website is
http://www.csiberkeley.com/) and is used for the structural design of
concrete slabs (and other things). Assume that there is a concentrated load on
a slab, and I need to decide how much steel reinforcement to place in
the slab to resist the bending moment caused by the load. I will need to
find out what is the maximum bending moment which the slab and its
reinforcement should cater for (which will be less than the very
maximum moment caused by the load at the point immediately underneath
it). I will input
the details of the load and slab into the SAFE program. I will also
need to input a value for the width of the strips into which I will
notionally divide
the slab.

Question: How do I decide what is the appropriate WIDTH OF THE STRIP
into which I should divide the slab, for purposes of calculating the
maximum bending moment? (This is the question to which I need a
textbook reference.)