dr-paul-toyne-gacso-role-of-sd-practitioner-may-2011 Leave a Comment / By Paul Toyne / September 18, 2016 dr-paul-toyne-gacso-role-of-sd-practitioner-may-2011 Co-authored by leading SD experts and myself. GACSO think-piece on the role of the SD practitoner. May 2011