National Transportation Safety Board conducted a public hearing during which witnesses testified about problems with the safetyculture at WMATA. The NTSB's
Uncommon Farmer. The Emergence of Genetics in the 20th century. Cold Springs Harbor Laboratory Press. 2003-08-15. ISBN 978-0-87969-688-7. 含有內容需登入查看的頁面 (link)
November 1999: 163. ISBN 978-0-06-019434-5. Boyle, Alan. 4,500-year-old harbor structures and papyrus texts unearthed in Egypt. NBC. 15 April 2013 [2017-12-22]