Christensen, Steen Winter, Peer Wille-Jørgensen, Arne Bjerg-nielsen, Per Hølmich, and Benn Duus. 1987. “Bleeding After Hip Arthroplasty Not Increased by Heparin Plus Dihydroergotamine”. Acta Orthopaedica 58 (2):104-5. https://doi.org/10.3109/17453678709146449.