Knut H. Borch, Ida Hansen-Krone, Sigrid K. Braekkan, Ellisiv B. Mathiesen, Inger Njolstad, Tom Wilsgaard, and John-Bjarne Hansen. 2010. “Physical Activity and Risk of Venous Thromboembolism. The Tromsø Study”. Haematologica 95 (12). Pavia, Italy, 2088-94. https://doi.org/10.3324/haematol.2009.020305.