There's also an earlier version: MATHEMATICS The Core Course for A-level
, for which Google provides a free preview. I would expect much of the material is the same. If anything, this earlier book would cover slightly more ground, as the core syllabus has been thinned a bit over the years. However, the latest edition presumably includes questions that occurred in more recent examinations, and may more accurately reflect current terminology.
Will you be specializing in mathematics or just doing examinations based on the core syllabus?