Text and Data Mining valid from 2019-01-05
Received: 12 April 2018
Accepted: 20 December 2018
First Online: 5 January 2019
Compliance with ethical standards
: This study was conducted according to the Declaration of Helsinki guidelines and approved by the Ethical Committee of Mazandaran University (Ethical cod #IR.BMSU.REC.1395.987).
: The authors declare that they have no conflict of interest.