Library of Congress Classification System
| Main Classes | Subclasses |
|---|---|
| A - General Works | AE - Encyclopedias AI - Indexes AN - Newspapers AP - Periodicals |
| B - Philosophy, Psychology | B-BD - Philosophy BF - Psychology BH - Esthetics BJ - Ethics BL-BX - Religions, Mythology |
| C - History (Auxiliary sciences: archaeology, genealogy, etc.) | (various) |
| D - History (except America) | DA - Great Britain DC - France DD - Germany DK - Russia DS - Asia DT - Africa |
| E-F - America and U. S. | F1-F970 - United States F1201-F3899 - Latin America |
| G - Geography, Anthropology | G-GF - Geography, Travel, Atlases GN - Anthropology, Ethnography GR - Folklore GV - Sports |
| H - Social Sciences | HA-HJ - Economics HM-HQ - Sociology HX - Communism, Socialism, Anarchism |
| J - Political Science | |
| K - Law | |
| L - Education | |
| M - Music | ML - Literature of Music MT - Musical Instruction |
| N - Fine Arts | NA - Architecture NB - Sculpture & Related Arts NC - Graphic Arts ND - Painting NK - Applied Arts NX - The arts in general |
| P - Language and Literature | PA - Classical Philology PB-PH - Modern European Languages PJ-PL - Oriental Languages PQ - Romance Literatures PR - English Literature PS - American Literature PT - German Literature |
| Q - Science | QA - Mathematics QB - Astronomy QC - Physics QD - Chemistry QE - Geology QH - Natural History QK - Botany QL - Zoology QM - Human Anatomy QP - Physiology QR - Bacteriology |
| R - Medicine | (various) |
| S - Agriculture | (various) |
| U - Military Science | |
| V - Naval Science | |
| T - Technology & Engineering | (various) |
| Z - Bibliography & Library Science |
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A+ Research & Writing for high school and college students was created by Kathryn L. Schwartz