- Correspondence Dr Karin Modig, Unit of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Box 210 Stockholm SE-171 76, Sweden;
- Received 26 May 2016
- Revised 4 October 2016
- Accepted 15 November 2016
- Published in print 1 May 2017.
- Published online 10 April 2017.
- Published first 14 March 2017.
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