Classification
150 - Psychology
303 - Social processes
330 - Economics
302 - Social interaction
2
384 - Communications; telecommunication
2
500 - Natural sciences & mathematics
2
153 - Mental processes & intelligence
1
158 - Applied psychology
1
380 - Commerce, communications & transportation
1
395 - Etiquette (Manners)
1
650 - Management & auxiliary services
1
658 - General management
1