Text and Data Mining valid from 2019-04-15
Received: 3 September 2018
Accepted: 27 March 2019
First Online: 15 April 2019
Ethics approval and consent to participate
: The study was reviewed and approved by the Bioethics Commission of the Medical Faculty at University of Rzeszow. Written informed consent was obtained from all the parents after being informed of the study objectives.
: Not applicable.
: The authors declare that they have no competing interests.
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