Distance education 30 University extension 9 Education, Higher 4 Open learning 4 Congresses 3 Correspondence schools and courses 3 Education, Rural 3 Academic libraries 2 Communication systems 2 Computer managed instruction 2 Computer-assisted instruction 2 Databases 2 Education 2 Education, Primary 2 Evaluation 2 Learning 2 Technological innovations 2 Vocational education 2 Adult education 1 Attitude 1 College dropouts 1 College students 1 College teachers 1 DEDATA (Information storage and retrieval systems) 1 Database design 1 Education, Nursing 1 Engineering 1 Faculty 1 Intelligent tutoring systems 1 Libraries and education 1