(2000). Percentage of Higher Education Institutions Offering Distance Ed Courses. U.S. Department of Education.
Chicago-viite (17. p.)Percentage of Higher Education Institutions Offering Distance Ed Courses. U.S. Department of Education, 2000.
MLA-viite (9. p.)Percentage of Higher Education Institutions Offering Distance Ed Courses. U.S. Department of Education, 2000.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.