نوع المادة
Electronic books
Internet resources
26
Problems, exercises, etc
14
Handbooks, manuals, etc
11
Outlines, syllabi, etc
6
Computer network resources
5
Formulae
4
Tables
3
Textbooks
3
Biography
2
Popular works
2
Case studies
1
Conference papers and proceedings
1
Congresses
1
Didactic fiction
1
Examinations, questions, etc
1
Fiction
1
Notebooks, sketchbooks, etc
1
Problems and exercises
1
Romance fiction
1
Study guides
1
Terminology
1