I am working on that grammar book. Bet it won't be a big seller on Leo. ;-)
#3 wrote: 'increasing number of' = 'more and more'
It is not the number that is providing, but the publications.
But it is "the" number that is increasing, so for me, "a/the number" is the subject, which would then normally take singular.
Isn't it about the number of publications that is increasing? What they provide is a different thought for me. We don't really have any context. Maybe that's irrelevant.
When people say it, however, or even in writing, in my opinion, at many levels, both versions come out "is + are". They both sound natural to me.
Anyway, ßarah, my intention was not to be misleading, but express my experience. One person (Artemis) did agree with me. ;-)
Anyway, you have a clear consensus, so disregard my comments!