In The Reflexes of the Proto-Indo-European Laryngeals in Celtic, Nicholas Zair for the first time collects all the words from the Celtic languages which contained a laryngeal, and identifies the regular results of the laryngeals in each phonetic environment.

The Prehistory of the Glottalic Theory; THE GLOTTALIC THEORY: Classic Statements of the Theory; Critical Responses; Refinements & Additional Variants. IMPLICATIONS OF THE GLOTTALIC THEORY: Reformulating Some Laws of IE; Dialectal Developments; Distant Genetic Relationships; KEY ISSUES AND SOME MIDDLE GROUND: The Traditional Plain Voiced Series; The Traditional Voiced Aspirate Series; THE CHRONOLOGICAL SOLUTION: On the Role of Typology in Reconstruction; Theoretical Issues; Phonetics & Phonology in Reconstruction; A Note on Linguistic Methodology; Summary; Conclusion, and Outlook.