Items in concurrency 2024 Self-Study in July 2024 Jul 1 2019 Self-Study in June 2019 Jun 1 2016 Self-Study in January 2016 Jan 1 2015 Self-Study in October 2015 Oct 1 2015 Self-Study in August 2015 Aug 2 2015 Self-study in June 2015 Jun 3