(2000). Percentage of Students Enrolled in Distance Education Courses: 1995. U.S. Department of Education.
Chicago Style aipamenaPercentage of Students Enrolled in Distance Education Courses: 1995. U.S. Department of Education, 2000.
MLA aipamenaPercentage of Students Enrolled in Distance Education Courses: 1995. U.S. Department of Education, 2000.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.