Related Clues:
- UK reference book
- 5 Placed inside: abbr.
- Venerable British ref. set
- Authoritative ref.
- Brit. ref. work
- Citation-filled ref.
- Ref. book whose first edition took 68 years to complete
- SASE, for example
- A-to-Zed ref.
- What's inside an env.
- 20-vol. reference
- Brit. dictionary
- Subj. of Simon Winchester's "The Meaning of Everything"
- Ltr. extra
- In this env.