Mogensen, B., Baldursson, H., Jónsson, G. T., & Baldursson, H. (1984). Proceedings of the Scandinavian Orthopaedic Association 42nd Assembly: Reykjavik, Iceland, June 13-16, 1984. Acta Orthopaedica, 55(6), 671–718. https://doi.org/10.3109/17453678408992421