To find books on your topic, follow these steps:
You might be able to find in OSCAR the archeological excavation reports for your site, but you will also find books on the history of the site, and other aspects. Remember to look at the bibliography in the books. It might give you the bibliographic information for the reports. Once you have this information, you can order the report through interlibrary loan.
If you don't find anything on your topic in OSCAR, go to LINK +, a catalog including the holdings of numerous California libraries. If you find a good book in LINK+, you can request it online. It will come within 3 days.