Elsevier require a specific licence for accepted author manuscripts. ENTER: © 2018. This version is made available under the CC-BY-NC-ND 4.0 license: https://creativecommons.org/licenses/by-nc-nd/4.0/  
Except where otherwise noted, this item's licence is described as Elsevier require a specific licence for accepted author manuscripts. ENTER: © 2018. This version is made available under the CC-BY-NC-ND 4.0 license: https://creativecommons.org/licenses/by-nc-nd/4.0/