The postthrombotic syndrome in relation to venous hemodynamics, as measured by means of duplex scanning and strain-gauge plethysmography - Haenen, JH; Janssen, MC; van Langen, H; van Asten, WN; Wollersheim, H; van’t Hof, MA; Skotnicki, SH; Thien, T (J Vasc Surg, 1999)