Terri Friedman, "Growing Up in Public II," Exhibited at Fredericks & Freiser, Fall 1997.
The above books are about sculpture in general, but may have some information about plastic.
There is more information available on Oxford Art Online, search for plastic to find general information articles about the material.
Search the library catalog for terms: plastic, plastic sculpture ...
Limit the location to Art Library and genre to Exhibitions.
Go to E-Resources by Discipline and select Art & Architecture.
Choose any of the databases (Art & Architecture Source is recommended).
Search for terms like plastic, plastic sculpture, etc. for scholarly articles about the material