Couperus, L. E.
Henkens, I. R.
Jongbloed, M. R. M.
Hazekamp, M. G.
Schalij, M. J.
Vliegen, H. W.
Article History
Received: 15 May 2015
Accepted: 8 March 2016
First Online: 20 April 2016
Conflict of interest
: L.E. Couperus, I.R. Henkens, M.R.M. Jongbloed, M.G. Hazekamp, M.J. Schalij and H.W. Vliegen states that there are no conflicts of interest.