الإتاحة: http://theses.mit.edu/Dienst/UI/2.0/Describe/0018.mit.theses%2f2000-20Testhttp://hdl.handle.net/1721.1/9241Test
الإتاحة: http://hdl.handle.net/1721.1/9241Testhttp://theses.mit.edu/Dienst/UI/2.0/Describe/0018.mit.theses%2f2000-20Test