Learn Celtic Languages Collection (Irish, Scottish Gaelic, Welsh, Breton)

Learning Irish + audio

Linguaphone Irish course + audio
Basic Irish : A grammar and workbook
Intermediate Irish : A grammar and workbook
Teach yourself complete Irish + audio
Teach yourself Irish 1993
Teach yourself Irish grammar
Colloquial Irish + audio
A learner's guide to irish
Speaking Irish An Ghaeilge Bheo + audio
Irish nouns a reference guide
Collins pocket Irish dictionary
The Cambridge companion to Modern Irish culture

Scottish Gaelic

Teach yourself Gaelic 1971
Scottish Gaelic in 3 months
Teach yourself Gaelic 1993 + audio
Teach yourself Gaelic conversation + audio
Colloquial Scottish Gaelic + audio
Scots Gaelic a brief introduction
A taste of Gaelic
Everyday Gaelic
Gaelic language practice
The Edinburgh companion to the Gaelic language
Gaelic verbs Systemised and simplified
Essential English-Gaelic dictionary
The Modern Gaelic-English dictionary

Welsh

Welsh in 3 months + audio
Colloquial Welsh +audio (Lessons 1-8 only)
Teach yourself Welsh 2003 + audio
Teach yourself Welsh 1992 + audio
Linguaphone Welsh course + audio
Modern Welsh a comprehensive grammar
The pocket Modern Welsh dictionary
The Collins Spurrell pocket Welsh dictionary
A dictionary of Welsh and English idiomatic phrases
The Welsh language and its social domains

Breton

Colloquial Breton + audio
Breton grammar

General

The Celtic languages 2nd edition (Routledge)
Celtic culture a historical encyclopedia