SUBJECT
Chemistry
Electronic books
161
Study and teaching
146
Study and teaching (Secondary)
132
Experiments
88
Laboratory manuals
88
Physics
83
Study and teaching (Higher)
55
Problems, exercises, etc
50
Biochemistry
44
Chemistry, Organic
39
History
38
Chemistry teachers
30
Congresses
28
Science
28
Data processing
27
Mathematics
26
Dyes and dyeing
24
Textbooks
24
Research
23
Academic achievement
22
Dictionaries
22
Attitudes
21
Chemistry, Analytic
21
High school students
20
Wood
18
Outlines, syllabi, etc
15
Chemistry, Physical and theoretical
14
Chemistry, Technical
14
Examinations
14
Tables
14
Textile fibers
14
Examinations, questions, etc
13
Programmed instruction
13
Chemists
12
Environmental chemistry
12
Qualitative
12
Biology
11
Chemical engineering
11
Chemistry, Inorganic
11
Analysis
10
Juvenile literature
10
Medicine
10
Physical sciences
10
Problem solving
10
Activity programs
9
Bibliography
9
Chemical reactions
9
Aids and devices
8
Pharmaceutical chemistry
8
more ...