You can easily search a majority of the Penn Libraries journal titles about Rheumatology in Browzine.
Rheumatology — Medical Specialties O-Z — University of Pennsylvania — BrowZine
Below are direct links to a selection of these titles.
Altas of nuclear medicine in musculoskeletal system: case oriented approach by 
Interdisciplinary Approaches to Overlap Disorders in Dermatology and Rheumatology by 
Current Diagnosis & Treatment in Rheumatology, Fourth Edition by 
Ultrasound in rheumatology: a practical guide for diagnosis by 
Diagnoses without names : challenges for medical care, research, and policy by 
