As you begin your research, you might find that you are unfamiliar with certain topics or language used in your discipline. Specialized philosophy reference sources such as encyclopedias and dictionaries can provide you with:
Introductions to major philosophers and their works
Definitions and overviews of topics
Bibliographies pointing you to more sources
Major events influencing the field
Historical timelines of philosophical works
Below are some key philosophy reference works you can consult as you begin and progress in your research.
The Shorter Routledge Encyclopedia of Philosophy by 
Routledge Encyclopedia of Philosophy
Encyclopedia of Classical Philosophy
American Philosophy: An Encyclopedia
Encyclopedia of Asian Philosophy
The Routledge Dictionary of Philosophy
The Cambridge Dictionary of Philosophy
New Dictionary of the History of Ideas
Dictionary of Cognitive Science
Historical Dictionary of Feminist Philosophy by
Having only emerged in the past few decades, Feminist Philosophy is rapidly developing its own thrust in areas of particular importance to feminism-and women more generally-while also reevaluating and reshaping most other fields of philosophy, from ethics to logic and Marxism to environmentalism. It draws not only on feminist philosophers but criticizes, approves, or appropriates the work of the leading philosophers of all times. The introduction to this reference work provides a useful overview of the subject area and the chronology runs the gamut from Ancient Greek philosophers to contemporary feminist ones. The cross-referenced dictionary entries cover both the central figures and ideas from the historical tradition of philosophy, as well as ideas and theories from contemporary feminist philosophy, such as epistemology (the philosophy of science) and topics that have been introduced by the feminist movement itself, like abortion and sexuality. In addition to including entries on Aristotle, Plato, Descartes, Kant, Wollstonecraft, Beauvoir, and Daly, relevant aspects of other fields of philosophy, the major concepts, and prevailing interpretations and conjectures are also covered. A comprehensive bibliography allows for further reading.
Dictionary of World Philosophy
Dictionary of Modern American Philosophers
Biographical Dictionary of Twentieth-Century Philosophers
