Text and Data Mining valid from 2018-12-15
Received: 31 October 2018
Accepted: 10 December 2018
First Online: 15 December 2018
Compliance with ethical standards
: With the submission of this manuscript, I would like to state that the authors report no conflict of interest concerning the materials and methods used or the findings specified in this paper. Furthermore, the authors declare that this study was performed in accordance to the research ethical guidelines.