sentences:  Dr. John Garang died in a plane crash and Mr. Abiel Alier with the team did their part to investigate the possible mechanical failure that led to the crash which was regionally blamed on a bad weather and lack of clear visibility although the Ugandan President Yoweri Museveni hinted that the possibility of a foul play was something that shouldn't be dismissed or disregarded.In early 1990s, Abel Alier wrote a book under the title "Southern Sudan