Reference work

Reference work (physical copy) 

The editor and publisher of a well-known reference work can be omitted, but cite the page numbers consulted:

Title. Edition (if not first edition). Year. s.v. Section heading, page number of your quotation.

Example:

New Encyclopaedia Britannica. 15th ed. 2005. s.v. Microradiography, p.1374.

s.v. stands for "sub verbo". This means "look under" and directs the reader to find it under another heading, in this case the section.

Use p. to reference a single page, and pp. for a range of pages.

Reference work (online) 

Electronic pocket dictionary

Title. [Name of e-dictionary reader]. Year. s.v. Section heading, page number of your quotation (if available).

Example

Oxford Crossword Dictionary. [Seiko ER3200 Oxford Crossword Solver Pocket Dictionary]. 2005. s.v. Microradiography, p.1374.