Green in Sherpa: Author can archive submitted version (i.e. pre-refereeing).
Author can archive accepted version (i.e. final draft post-refereeing).
Author can archive publisher's version / PDF.
Conditions: 
    On open access repositories
    Publisher's version/PDF may be used
    Published source must be acknowledged
    Creative Commons Attribution License 4.0
    Authors retain copyright
    Authors are encouraged to submit their published articles to institutional repositories
    All titles are open access journals. --
Full-txt added, 7.6.18-MMM