Gramophone Archive is an invaluable source of information on several trends of music, including British dance bands of the Swing Era. While The Melody Maker's online archive is still a dream, this is THE ONLY knowledge base available worldwide.
However, 1) many pages of early decades are skipped (on purpose?), and 2) many pages are recognized so poorly that one could hardly read them. Plus, 3) the scans themselves (pictures) should be larger - to read, proofread, to be able to distinguish titles and authors' signatures, which are often omitted in recognized text (which makes it an invalid reference, you know).