HD 22/12/17. -- 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: cross author cannot archive publisher's version/PDF General Conditions: On author's personal website, employer's website, institutional repository, non-commercial subject repository, and Scholarly Collaboration Networks that have signed up to the Voluntary STM Sharing Principles Author's post-print can be deposited upon publication Must link to publisher version with DOI Published source must be acknowledged with citation Publisher's version/PDF cannot be used. -- Accepted v. requested (Van Staden), 12.2.18-MMM