Releasing album pages stuck together

[RobinClay]

In one of my parents' albums, two of the pages have become stuck together.  Luckily, they pages are removable.  Obviously I don't know what was fixed to each face, but almost certainly some photographs, and possibly just paper, e.g. theatre programmes or telegrams.

I have tried nothing so far to separate them (except minimal force, of course). 

What do you suggest I try first ?

[Treetotal]

I would take it to a professional photographer for advice...there may be a very easy solution from someone in the know.
Carol