Espehaug, B. et al. 1999. The effect of hospital-type and operating volume on the survival of hip replacements: A review of 39,505 primary total hip replacements reported to the Norwegian Arthroplasty Register, 1988-1996. Acta Orthopaedica. 70, 1 (Jan. 1999), 12–18. DOI:https://doi.org/10.3109/17453679909000949.