You can filter out a lot of the chaff by restricting your search to the .edu domain, e.g. "intercropping site:.edu" gives:
Both of these papers provide references to dead-tree publications. Access to some of these may require a visit to a university or other large library.
Unfortunately, neither paper is really aimed at home gardeners -- most are geared towards large scale agriculture. And, given that this is where research dollars come from, I suspect that much of the research is going to be targeted to this area. You might, however, be able to find research on vegetable intercropping for large market growers that transfers well to the home garden.
Another possible source of information, and a synonym to search on, is plant "guilds". This is a related, but somewhat deeper and richer concept than interplanting. Permaculture uses the concept of plant guilds to build "stacks" of plants that work well together, from the root zone to the tree canopy. You are likely to find more practical experience than scientific research. Some of it will be very localized -- since the specific plant communities that work well together will be different on different sites. In my experience, this research has less junk science than the biodynamic nonsense that's out there. However, since it is less formal and not coming from a rigorous scientific community, there are fewer references so you can't quickly build a long bibliography of articles to read. A good starting point with lots of tables and plant lists is "Gaia's Garden" by Toby Hemenway.