If you have a (free) account, you can check this book out online for an hour and peruse it. It covers ACI 318-71.
As a side note, this is the first ACI that had two-way slabs being designed for the full statical (wl2/8) moment..... (took them a bit to do that, it's discussed in my copy of Reinforced Concrete, Mechanics and Design, 2nd edition, MacGregor, 1983). Chapter 13.2 History of two-way slabs. (That's an ebay link, in case you're curious what the cover looks like, a bit tough to find).
