How to Search an Online Library Catalog

The Library of Congress System

Many college and university libraries use the Library of Congress Classification System to organize their collections. By searching your online library catalog for specific subject headings, you can identify sources that are relevant to your research writing project. You can view the complete classification system at the Library of Congress Web site.

A	General Works
AC	Collections. Series. Collected works
AE	Encyclopedias
AG	Dictionaries and other general reference works
AI	Indexes
AM	Museums. Collectors and collecting
AN	Newspapers
AP	Periodicals
AS	Academies and learned societies
AY	Yearbooks. Almanacs. Directories
AZ	History of scholarship and learning. The humanities
	
B	Philosophy. Psychology. Religion
B	Philosophy (General)
BC	Logic
BD	Speculative philosophy
BF	Psychology
BH	Aesthetics
BJ	Ethics
BL	Religion. Mythology. Rationalism
BM	Judaism
BP	Islam. Bahaism. Theosophy, etc.
BQ	Buddhism
BR	Christianity
BS	The Bible
BT	Doctrinal Theology
BV	Practical Theology
BX	Christian Denominations
	

C	Auxiliary Sciences of History
C	Auxiliary Sciences of History (General)
CB	History of Civilization
CC	Archaeology
CD	Diplomatics. Archives. Seals
CE	Technical chronology. Calendar
CJ	Numismatics
CN	Inscriptions. Epigraphy
CR	Heraldry
CS	Genealogy
CT	Biography
	
D	History: General and History of Europe
D	History (General)
DA	Great Britain
DAW	Central Europe
DB	Austria—Liechtenstein—Hungary—Czechoslavakia
DC	France—Andorra—Monaco
DD	Germany
DE	The Greco-Roman World
DF	Greece
DG	Italy—Malta
DH	Low Countries—Benelux Countries
DJ	Netherlands (Holland)
DJK	Eastern Europe (General)
DK	Russia. Soviet Union. Former Soviet Republics—Poland
DL	Northern Europe. Scandinavia
DP	Spain—Portugal
DQ	Switzerland
DR	Balkan Peninsula
DS	Asia
DT	Africa
DU	Oceania (South Seas)
DX	Gypsies
	
E	History: America

11	America
151	United States
	
F	History: America
1	United States local history
1001	British America (including Canada)
	Dutch America
1170	French America
1201	Latin America. Spanish America
	
G	Geography. Anthropology. Recreation
G	Geography (General). Atlases. Maps
GA	Mathematical geography. Cartography
GB	Physical geography
GC	Oceanography
GE	Environmental sciences
GF	Human ecology. Anthropogeography
GN	Anthropology
GR	Folklore
GT	Manners and customs (General)
GV	Recreation. Leisure
	
H	Social Sciences
H	Social sciences (General)
HA	Statistics
HB	Economic theory. Demography
HC	Economic history and conditions
HD	Industries. Land use. Labor
HE	Transportation and communications
HF	Commerce
HG	Finance
HJ	Public finance
HM	Sociology (General)
HN	Social history and conditions. Social problems. Social reform
HQ	The family. Marriage. Women
HS	Societies: secret, benevolent, etc.
HT	Communities. Classes. Races
HV	Social pathology. Social and public welfare. Criminology
HX	Socialism. Communism. Anarchism
	
J	Political Science
J	General legislative and executive papers
JA	Political science (General)
JC	Political theory
JF	Political institutions and public administration—General
JK	Political institutions and public administration—United States
JL	Political institutions and public administration
	—Canada, West Indies, Mexico, Central and South America
JN	Political institutions and public administration—Europe
JQ	Political institutions and public administration
	—Asia, Arab countries, Islamic countries, Africa, Atlantic 
	Ocean islands, Australia, New Zealand, Pacific Ocean islands
JS	Local government. Municipal government
JV	Colonies and colonization. Emigration and immigration. 
	International migration
JZ	International relations
	

K	Law
K	Law in general. Comparative and uniform law. Jurisprudence
KD	United Kingdom and Ireland
KE	Canada
KF	United States
KG	Latin America—Mexico and Central America
	—West Indies. Caribbean area
KH	South America
KJ	Europe
	
L	Education
L	Education (General)
LA	History of education
LB	Theory and practice of education
LC	Social aspects of education
LD	Individual institutions—United States
LE	Individual institutions—America (except United States) 
LF	Individual institutions—Europe
LG	Individual institutions—Asia, Africa, Pacific Islands
LH	College and school magazines and papers
LJ	Student fraternities and societies, United States
LT	Textbooks
	
M	Music and Books on Music
M	Instrumental and vocal music
ML	Literature on music
MT	Musical instruction and study
	
N	Fine Arts

N	Visual arts
NA	Architecture
NB	Sculpture
NC	Drawing. Design. Illustration
ND	Painting
NE	Print media
NK	Decorative arts
NX	Arts in general
	
P	Language and Literature
P	Philology. Linguistics
PA	Greek language and literature. Latin language and literature
PB	Modern languages. Celtic languages
PC	Romance languages
PD	Germanic languages. Scandinavian languages
PE	English language
PF	West Germanic languages
PG	Slavic languages. Baltic languages. Albanian language
PH	Uralic languages. Basque language
PJ	Oriental languages and literatures
PK	Indo-Iranian languages and literatures
PL	Languages and literatures of East Asia, Africa, Oceania
PM	Hyperborean, Indian, and artificial languages
PN	Literature (General)
PQ	French literature—Italian literature—Spanish literature
	—Portuguese literature
PR	English literature
PS	American literature
PT	German literature—Dutch literature—Flemish literature
	—Afrikaans literature—Scandinavian literature
PZ	Fiction and juvenile belles lettres
	
Q	Science
Q	Science (General)
QA	Mathematics
QB	Astronomy
QC	Physics
QD	Chemistry
QE	Geology
QH	Natural history—Biology
QK	Botany
QL	Zoology
QM	Human anatomy
QP	Physiology
QR	Microbiology
	
R	Medicine

R	Medicine (General)
RA	Public aspects of medicine
RB	Pathology
RC	Internal medicine
RD	Surgery
RE	Ophthalmology
RF	Otorhinolaryngology
RG	Gynecology and obstetrics
RJ	Pediatrics
RK	Dentistry
RL	Dermatology
RM	Therapeutics. Pharmacology
RS	Pharmacy and materia medica
RT	Nursing
RV	Botanic, Thomsonian, and eclectic medicine
RX	Homeopathy
RZ	Other systems of medicine
	
S	Agriculture
S	Agriculture (General)
SB	Plant culture
SD	Forestry
SF	Animal culture
SH	Aquaculture. Fisheries. Angling
SK	Hunting sports
	
T	Technology
T	Technology (General)
TA	Engineering (General). Civil engineering
TC	Hydraulic engineering. Ocean engineering
TD	Environmental technology. Sanitary engineering
TE	Highway engineering. Roads and pavements
TF	Railroad engineering and operation
TG	Bridge engineering
TH	Building construction
TJ	Mechanical engineering and machinery
TK	Electrical engineering. Electronics. Nuclear engineering
TL	Motor vehicles. Aeronautics. Astronautics
TN	Mining engineering. Metallurgy
TP	Chemical technology
TR	Photography
TS	Manufactures
TT	Handicrafts. Arts and crafts
TX	Home economics
	
U	Military Science
U	Military science (General)
UA	Armies: Organization, distribution, military situation
UB	Military administration
UC	Maintenance and transportation
UD	Infantry
UE	Cavalry. Armor
UF	Artillery
UG	Military engineering. Air forces
UH	Other services
	
V	Naval Science
V	Naval science (General)
VA	Navies: Organization, distribution, naval situation
VB	Naval administration
VC	Naval maintenance
VD	Naval seamen
VE	Marines
VF	Naval ordnance
VG	Minor services of navies
VK	Navigation. Merchant marine
VM	Naval architecture. Shipbuilding. Marine engineering
	
Z	Bibliography. Library Science. Information Resources (General)
Z	Books (General)
ZA	Information resources (General)