Christensen, S. W., Wille-Jørgensen, P., Bjerg-nielsen, A., Hølmich, P., & Duus, B. (1987). Bleeding after hip arthroplasty not increased by heparin plus dihydroergotamine. Acta Orthopaedica, 58(2), 104–105. https://doi.org/10.3109/17453678709146449