Text and Data Mining valid from 2017-10-28
Received: 6 October 2017
Accepted: 11 October 2017
First Online: 28 October 2017
Compliance with Ethical Standards
: Investigations were approved by the Institutional Ethical Review Board. / The study protocol was approved by the Ethics and Scientific committee of the participating institution. TUKEB 7/2006.
: All of the authors declare that they have no competing interests. All authors have read and approved the final manuscript.