Xénero
Libros electrónicos
55
Internet videos
25
Electronic journals
15
Periodicals
14
Périodiques
10
Problems, exercises, etc
9
Electronic books
7
Textbooks
3
Outlines, syllabi, etc
2
Problemas
2
Problemas, ejercicios, etc
2
Abstracts
1
Congresos
1
Congresos y asambleas
1
Congresses
1
Handbooks, manuals, etc
1
Internet resources
1
Libros electr{acute}onicos
1
Study and teaching
1