LL 12/7/17. --
Green in Sherpa: Author's Pre-print: 	green tick  author can archive pre-print (ie pre-refereeing)
Author's Post-print: 	green tick  author can archive post-print (ie final draft post-refereeing)
Publisher's Version/PDF: 	green tick  author can archive publisher's version/PDF
General Conditions: 	

    On open access repositories
    Publisher's version/PDF may be used
    Authors retain copyright
    Creative Commons Attribution License
    Published source must be acknowledged with citation
    Must link to publisher version with DOI
    Must state license. 
This an open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license. --
Full-text added 26.7.17-MMM