1. The aetiology of primary protrusio acetabuli;Alexander, C.;British Journal ofRadiology,1965
2. Primary protrusion of the acetabulum;Bilfield, B.S.; Janecki, C.J.; Evarts, C.M.;Clinical Orthopaedics,1973
3. Chrobak) Beitrdge zur Geburtshilfe und;Eppinger, H.;Gyndkologie,1903
4. Protrus; o acetabuli;Friedenberg, Z.B.;Ametican Journal of Surgery,1953
5. Adolescent deformities of the acetabulum and investigation into the nature of protrusio acetabuli;Gilmour, J.;British Journal ofSurgery,1939