Text and Data Mining valid from 2018-04-03
Received: 25 October 2017
Accepted: 21 March 2018
First Online: 3 April 2018
Ethics approval and consent to participate
: The study was approved by the Bioethics Committee of the Medical University of Bialystok (Resolution no. R-I-002/310/2013). Participants of this study gave their verbal consent to participate.
: Not applicable.
: The authors declare that they have no competing interests.
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