Comparison between coagulation factor VIII quantified with one-stage activity assay and with mass spectrometry in haemophilia A patients: Proof of principle. - Donners AAMT; van Maarseveen EM; Weetink YRJ; El Amrani M; Fischer K; Rademaker CMA; Egberts TCG; Huisman A; Musson REA (International journal of laboratory hematology, 2020)