Andersen, L.J. et al. 2007. Postoperative analgesia in total hip arthroplasty: A randomized double-blinded, placebo-controlled study on peroperative and postoperative ropivacaine, ketorolac, and adrenaline wound infiltration. Acta Orthopaedica. 78, 2 (Jan. 2007), 187–192. DOI:https://doi.org/10.1080/17453670710013663.