HD 21/7/16. -
Blue in Sherpa: Author's Pre-print: 	archiving status unclear
Author's Post-print: 	author can archive post-print (ie final draft post-refereeing)
Publisher's Version/PDF: archiving status unknown
General Conditions:  Authors retain copyright
    Creative Commons License available for selected titles
    Selected titles allow, authors to put work in Public Domain, 7.9.16--MMM