Complex sentence: In 1987 he resigned from his job, teaching, and in 1988 Mr. Siriwardena joined Vidusara science magazine as a Sub editor.Then he became the deputy editor of Vathmana magazine.
Split into simpler sentences: In 1987 he resigned from his job, teaching, and in 1988 Mr. Siriwardena joined Vidusara science magazine as a Sub editor. Latter he became the deputy editor of Vathmana magazine.