OA - HD 7/6/17. -- 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 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, -- Full-text added, 13.6.17-MMM