Είδος
Electronic books
621
Case studies
31
Filmed interviews
17
Libros electronicos
13
Educational films
12
Handbooks, manuals, etc
11
Periodicals
11
Instructional films
9
Filmed lectures
7
Electronic book
6
Congresses
5
Documentary films
3
Short films
3
Biography
2
Electronic journals
2
Anecdotes
1
Bibliography
1
Charts, diagrams, etc
1
Fiction
1
Interviews
1
Problems, exercises, etc
1
Research
1
Statistical methods
1