where the writers are
Feedback wanted.

I was wondering if any on here know of where to find research on parallel time periods?  Where two time periods co-exist.  I have had "Timeline" by Michael Crichton and "The Talisman" by Stephen King mentioned.  Also, quantum physics and holographic universe. 

I know this isn't a new concept but I don't know where to look for the research I am needing.