Classification
300 - Social sciences
1
306 - Culture & institutions
1
321 - Systems of governments & states
1
325 - International migration & colonization
1
331 - Labor economics
1
390 - Customs, etiquette & folklore
2
510 - Mathematics
1
570 - Life sciences; biology
1
573 - Specific physiological systems in animals
1
577 - Ecology
4
940 - History of Europe
1