| Library of Congress Classification | 
| Class | 
Subject | 
| A | 
General Works | 
| B | 
Philosophy Psychology Religion | 
| B | 
Philosophy | 
| BC | 
Logic | 
| BF | 
Psychology | 
| BL | 
Religions | 
| BF | 
Psychology | 
| C | 
Auxiliary Sciences of History | 
| D | 
History: General and Old World | 
| D | 
History | 
| DA | 
Great Britain | 
| DC | 
France | 
| DS | 
Asia | 
| E-F | 
America United States Local History | 
| G | 
Geography Anthropology | 
| G | 
Geography(General), Maps | 
| GB | 
Physical Geography | 
| GC | 
Oceanography | 
| GF | 
Human Ecology, Anthropogeography | 
| GN | 
Anthropology | 
| GV | 
Recreation, Leisure | 
| H | 
Social Sciences | 
| HB | 
Economic Theory Demography | 
| HD | 
Economic History and Conditions | 
| HE | 
Transportation and Communications | 
| HF | 
Commerce | 
| HG | 
Finance | 
| HM | 
Sociology | 
| J | 
Political Science | 
| JC | 
Political Theory | 
| JX | 
International Law Relations | 
| K | 
Law | 
| L | 
Education | 
| M | 
Music | 
| N | 
Fine Arts | 
| NA | 
Architeture | 
| NC | 
Drawing Design Illustration | 
| ND | 
Painting | 
| NE | 
Print Media | 
| NK | 
Decorative Arts Applied Arts | 
| NX | 
Arts in General | 
| P | 
Language and Literature | 
| P | 
Philology and Linguistics | 
| PE | 
English | 
| PL | 
Language and Literatures of Asia | 
| PN | 
Literary History and Collections | 
| Q | 
Science | 
| Q | 
Science(General) | 
| QA | 
Mathematics | 
| QB | 
Astronomy | 
| QD | 
Chemistry | 
| QE | 
Geology | 
| QH | 
Natural History Biology | 
| R | 
Medicine | 
| S | 
Agriculture | 
| SB | 
Plant Culture | 
| SD | 
Forestry | 
| T | 
Technology | 
| T | 
Technology(General) | 
| TA | 
Engineering Civil Engineering | 
| TC | 
Hydraulic Engineering | 
| TD | 
Environmental Technology | 
| TE | 
Highway Engineering Road | 
| TG | 
Bridge Engineering | 
| TR | 
Photography | 
| TH | 
Building Construction | 
| TH | 
Building Construction | 
| TJ | 
Mechanical Engineering | 
| TK | 
Electrical Engineering | 
| TL | 
Motor Vehicles, Aeronautics | 
| TN | 
Mining Engineering | 
| TP | 
Chemical Technology | 
| U-V | 
Military Science, Naval Science | 
| Z | 
Bibliography Library Science |