Röhrl, S. M., Nivbrant, B., Snorrason, F., Kärrholm, J., & Nilsson, K. G. (2006). Porous-coated cups fixed with screws: A 12-year clinical and radiostereometric follow-up study of 50 hips. Acta Orthopaedica, 77(3), 393–401. https://doi.org/10.1080/17453670610046316