Text and Data Mining valid from 2018-09-25
Received: 23 October 2017
Accepted: 19 September 2018
First Online: 25 September 2018
Ethics approval and consent to participate
: The Ethical Committee of the Medical University of Lublin approved the study protocol (No. KE-0254/75/211). From all children’s parents written informed consent was obtained.
: Not applicable.
: The authors declare that they have no competing interests.
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