I completely agree that the dependence on Kinsey (who himself cites a vast array of other sources including some of the ones I previously mentioned) is a weakness in the article. The Wikipedia entry then appears to be summarising his book rather than using it as a partial reference. Kinsey has a new book coming out on the Elstree years which will no doubt be useful in this department, alongside the other books. However, I would have thought that the purpose of a further reading list is to provide other sources of information on a subject that the reader of the Wikipedia article can consult to find out more about Hammer in this instance. The Bibliography on this page does not include all the book sources cited in the references either. I'd suggest adding these at the very least. The books I'm thinking of cover far more than this article has scope to, and thus I believe should be included.