Classification
320 - Political science
330 - Economics
414 - Phonology & phonetics
620 - Engineering & allied operations
700 - The arts; fine & decorative arts
2
000 - Computer science, information & general works
1
170 - Ethics
1
333 - Economics of land & energy
1
380 - Commerce, communications & transportation
1
500 - Natural sciences & mathematics
1
551 - Geology, hydrology & meteorology
1
581 - Specific topics in natural history
1
600 - Technology
1
900 - History & geography
1