It's called having an opinion.
You want to disagree; that's fine with me pal.
You'll notice this thread is based on people's opinions; therefore the "sources" you want cannot be quantified in books (although there are a few books that say Cilla was a golddigger; perhaps you've read them?). Obviously, only the woman herself knows.
So, on any threads where we're talking about factual information, the sources are widely available.
But for these types of threads, most of us can remain polite and pleasant until someone else launches an oblique personal attack.