Abstract (2015) - Philip J. Vardon (author), P.J. Vardon (author), Phil J. Vardon (author), Phil Vardon (author), PJ Vardon (author), P. J. Vardon (author), Philip James Vardon (author), P. Arnold (author), P Arnold (author), Patrick Arnold (author), M Milioritsas (author), MA Hicks (author), M.A. Hicks (author), Michael Anthony Hicks (author), M. Hicks (author), Michael A. Hicks (author), Michael Hicks (author), M. A. Hicks (author), PA Fokker (author), JH Fokkens (author)