van der Werf, Ilse M
Buiting, Karin
Czeschik, Christina
Reyniers, Edwin
Vandeweyer, Geert
Vanhaesebrouck, Piet
Lüdecke, Hermann-Josef
Wieczorek, Dagmar
Horsthemke, Bernhard
Mortier, Geert
Leroy, Jules G
Kooy, R Frank
Article History
Received: 22 February 2016
Revised: 31 May 2016
Accepted: 7 June 2016
First Online: 13 July 2016
Competing interests
: The authors declare no conflict of interest.