Text and Data Mining valid from 2019-08-13
Received: 16 April 2019
Revised: 2 August 2019
Accepted: 5 August 2019
First Online: 13 August 2019
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: For the present study formal consent is not required; for this type of study informed consent is not required. Privacy consent was obtained for every individual person’s data included in the study; for this type of study consent for publication is not required.