google reflectix insulation, just another company selling foil bubble wwrap, [i'm not recomending their product] but one of the first and distributed it in stores so they got sued a lot, and via settlement started posting honest installed Rvalues. Look at there installed listings, like Attic, Crawl Space, etc for effective installed values. I believe they have a whole house charts showing examples used all over [keep in mind it's restricted to their specific conditions.]
google how radiant barriers work and you'll get the same concepts. from reputable sources. or google 'convection, conduction, radiation heat energy' to get a low down on heat transfer.
Building Science Corporation is probably one of the best sites for actual real building science; plenty of case studies, and i'm sure an explanation there.
you won't find a lot of info because most reputable building sources understand that there isn't much advantage except for very specific cases to use such radiant barriers, and there are often tricky details to manage. Rvalues for most radiant barriers going up, or horizontal in walls are similar to common insulation that is often cheaper and easier to install. It only became popular as disreputable firms could crank the stuff out cheap and make confusing claims - it is in no way new. It's why common foil backed poly-iso has never had the wild Rvalue claims for the radiant barrier, as it was produced by large reputable firms, although it can be used to achieve additional Rvalue.
just remember a radiant barrier is intended to prevent heat transfer via radiation due to the low emittance of the radiant barrier, ie the low ability to radiate heat from itself.