Classics

Reference works are authoritative works that you can consult for specialized information to help get you started on a research topic.  There are many types of reference work, including dictionaries, encyclopedias, bibliographies, atlases, thesauri, directories, almanacs, style manuals and handbooks. 

Dictionaries

The Brill dictionary of Ancient Greek  
The English translation of Franco Montanari's Vocabolario della Lingua Greca. With 140,000 entries this is the most important modern dictionary for Ancient Greek and an invaluable tool for students and advanced scholars alike.

Database of Latin Dictionaries  
Database of Latin Dictionaries searches across over 20 dictionaries of the Latin language (including Latin-English and Latin-French dictionaries). These include dictionaries of Latin in Antiquity, the Patristic Period, and the Middle Ages and Early Modern Period, as well as thematic, linguistic, and medieval dictionaries.

Diogenes
Software for Classics, including a version of the Lewis and Short Latin dictionary [LSJ]. A tool for searching and browsing databases of ancient texts. There are web-based (DiogenesWeb) and desktop versions. For the desktop version, instructions are given for Mac, Windows and LINUX.

 Oxford Classical Dictionary, 3rd ed. 
The Oxford Classical Dictionary includes articles and definitions regarding literature, art, philosophy, law, biography, mythology, science, geography, daily life, and broad cultural and historical trends.

Thesaurus Linguae Latinae
TLL covers the Latin language as recorded in printed manuscripts dating from the classical period through 600 A.D. Each entry includes a list of all the sources referenced in creating the entry.

WORDS Latin-to-English & English-to-Latin Dictionary  by William Whitaker
Provides online translations from Latin to English and English to Latin.

Encyclopedias

Brill's New Pauly Online
The full-text New Pauly encyclopaedia of the ancient world. (netID required)

Internet Encyclopedia of Philosophy
A fully searchable online encyclopedia, featuring articles written by professional philosophers. Includes a section on Ancient Philosophy.

Stanford Encyclopedia of Philosophy
A dynamic encyclopedia, in which each entry is maintained and kept up to date by an expert or a group of experts in the field.

Paulys Realencyclopädie der classischen Altertumswissenschaft
The origin Pauly encyclopedia in German online.  Provides a list of articles from which to link.

Prosopographies

Digital Prosopography of the Roman Republic (DPRR)
Searchable database for prosopographical research on the elite of the Roman Republic, bringing together information about individual careers, office holdings, personal status, life dates and family relationships.

Language Dictionaries

Greek-English Lexicon (Liddell and Scott)
[also available via Perseus, 1940 via Perseus under PhiloLogic , 1883 via archive.org]
LIBRARY ANNEX - PA445.E5L6 1996, SMITH LIBRARY REF - PA445 L712G 1996

A Latin Dictionary (Lewis and Short)
[also available via Perseus and via archive.org 1891 edition]
DOUGLASS LIBRARY REF - PA2365.E5A52 1879, LIBRARY ANNEX - PA2365.E5A7 2002

Oxford Latin Dictionary
ART LIBRARY REF, CARR REF, LAW LIBRARY CAMDEN 4TH FLOOR - PA2365.E5O9 1982

Thesaurus Linguae Latinae
[public domain vols. available from HathiTrust and Bayerische Akademie der Wissenschaften]
ALEXANDER REF PA2361.T413

The Classical World

Aufstieg und Niedergang der römischen Welt: Geschichte und Kultur Roms im Spiegel der neueren Forschung . ed. Hildegard Temporini.
[limited preview available through archives.org, requires a free account]
Berlin, New York, De Gruyter, 1972- parts 1 and 2.
ALEXANDER STACKS - DG209.T36

Brill's New Pauly: Encyclopaedia of the Ancient World
[Available through Brill's New Pauly Database]

The Cambridge Ancient History
DANA REF - D57.C32 1982, ROBESON STACKS D57.C32 1982, CARR STACKS D57.C252, ALEX REF - D57.C32 1982
[Also available in Cambridge Histories Online]

Der Neue Pauly: Enzyklopädie der Antike
[Available through Brill's New Pauly Database]

The Oxford Classical Dictionary , 3rd ed.
ALEXANDER REF, CAMDEN REF - DE5.O9 2003

The Oxford Companion to Classical Civilization
ALEXANDER STACKS, DOUGLASS REF - DE5.O9 1998

Paulys Realencyclopädie der classischen Altertumswissenschaft. Neue Bearbeitung unter Mitwirkung zahlreicher Fachgenossen , ed. Georg Wissowa (Stuttgart, Druckenmüller Verlag, 1893- [1956- ]).
[pubic domain vols. available in the Internet Archive]
ALEXANDER REF - DE5 .P33, DANA REF - DE5 .P331

The Prosopography of the Later Roman Empire
ALEXANDER REF - DE5.P33, DANA REF - DE5.P331

Classical Philosophy

Classics of Western Philosophy , 6th ed.
ALEXANDER STACKS, CARR STACKS - B29.C536 2002

Encyclopedia of Classical Philosophy
ALEXANDER - REF B163.E53 1996

Classical Literature

The Oxford Companion to Classical Literature
DANA REF, DOUGLASS REF, ROBESON REF - PA31.H69 1989

Enciclopedia Virgiliana
LIBRARY ANNEX - PA6825.A3 1984

Orazio: Enciclopedia Oraziana
LIBRARY ANNEX - PA6411.O72 1996

Inscriptions, Images and Objects

Corpus Inscriptionum Latinarum
[many vols. available via CIL Open Access]
ALEXANDER Folio - CN520.C6

 Corpus Vasorum Antiquorum
[many vols. available via the CVA Online]
ART LIBRARY Oversize - NK4640.C6

Lexicon iconographicum mythologiae classicae (LIMC)
ART LIBRARY REFERENCE - N7760.L4 1981
[Online database (complement, and not replacement, to LIMC)]

 Supplementum Epigraphicum Graecum (SEG)
Alexander Library and Annex - CN360.S8