Havelin, Leif I, Anne M Fenstad, Roger Salomonsson, Frank Mehnert, Ove Furnes, Søren Overgaard, Alma B Pedersen, Peter Herberts, Johan Kärrholm, and Göran Garellick. 2009. “The Nordic Arthroplasty Register Association”. Acta Orthopaedica 80 (4):393-401. https://doi.org/10.3109/17453670903039544.