Funding for this research was provided by:
Ferdowsi University of Mashhad (3/20623)
Text and Data Mining valid from 2019-06-05
Received: 30 November 2018
Revised: 28 May 2019
Accepted: 30 May 2019
First Online: 5 June 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures were approved by the Ferdowsi University of Mashhad (Research Ethics Charter, The Ministry of Science, Research and Technology of Iran: 2575803/2012).