Belgers, M
Leenaars, M
Homberg, J R
Ritskes-Hoitinga, M
Schellekens, A F A
Hooijmans, C R
Article History
Received: 8 October 2015
Revised: 4 March 2016
Accepted: 17 March 2016
First Online: 31 May 2016
Competing interests
: The authors declare no conflict of interest.