If you had to buy one Rheumatology text book, I can assure you that this would be the one you might want to get.
Dr Jeremy Sager
This is a comprehensive, well written and easy to follow reference book... I would recommend this book to anyone as essential for all staff.
British Health Professionals in Rheumatology
If you are managing rheumatology problems, this is an extremely useful book to have on your shelf; if you are presented with a clinical conundrum and require more detail, this is the ideal book to refer to because both common and rare conditions are comprehensively covered. This book is strongly recommended
Dr Hedley Berry, Consultant Rheumatologist, London, International Musculoskeletal Medicine 31.4