. 2020 Aug 20;10(3):832–847. doi: 10.3390/ejihpe10030060
© 2020 by the authors.
Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Figure 5.
Evolution of keywords between intervals.