1. Disorders of the patello-femoral joint;Fulkerson,1977
2. A rational approach to treatment of patellofemoral pain;Radin;Clin. Orthop.,1979
3. Injuries to the cartilages of the patella and the femoral condyle;Chaklin;J. Bone Joint Surg.,1939
4. Chondromalacia patellae: a prospective study;Insall;J. Bone Joint Surg. (Am.),1976
5. Classification of patellofemoral disorders;Merchant;Arthroscopy,1988