Authors’ contributions

M.R. Schipper	Substantial contributions to conception and design, analysis and interpretation of data. Drafting the article and revising the article critically for important intellectual content. Final approval of the version to be published.
N. Vlegels	Substantial contributions to conception and design, analysis and interpretation of data. Drafting the article and revising the article critically for important intellectual content. Final approval of the version to be published.
T.W. van Harten	Substantial contributions to acquisition of data, analysis and interpretation of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
I. Rasing	Substantial contributions to acquisition of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
E.A. Koemans	Substantial contributions to acquisition of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
S. Voigt	Substantial contributions to acquisition of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
A. de Luca	Substantial contributions to analysis and interpretation of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
K. Kaushik	Substantial contributions to acquisition of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
E.S. van Etten	Substantial contributions to conception and design and to analysis and interpretation of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
E.W. van Zwet	Substantial contributions to analysis and interpretation of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
G.M. Terwindt	Substantial contributions to conception and design and to analysis and interpretation of data. Revising the article critically for important intellectual content. Final approval of the version to be published.
G.J. Biessels	Substantial contributions to conception and design. Revising the article critically for important intellectual content. Final approval of the version to be published.
M.J.P. van Osch	Substantial contributions to conception and design and to analysis and interpretation of data.. Revising the article critically for important intellectual content. Final approval of the version to be published.
M.A.A. van Walderveen	Substantial contributions to conception and design and to analysis and interpretation of data.. Revising the article critically for important intellectual content. Final approval of the version to be published.
M.J.H. Wermer	Substantial contributions to conception and design and to analysis and interpretation of data. Revising the article critically for important intellectual content. Final approval of the version to be published.