Related Clues:
- Cause of an env. bulge
- Massive ref
- Ltr.-bottom letters
- Venerable ref
- Massive Brit. reference
- Ref. wk
- In the env
- Ref. with about 22,000 pages
- Bottom-of-letter abbr
- SASE, perhaps: Abbr
- Heavy ref
- Ltr. in an envelope
- Work that's been punningly called a 'lex icon': Abbr
- UK reference
- Word ref. started in 1857