Memoire sur le systeme primitif des voyelles dans les langues indo-europeennes - Ferdinand de Saussure - Bog

Using comparison and internal reconstruction, Saussure's Memoire solved a long-standing linguistic problem by proposing the existence of two further sonant coefficients in Proto-Indo-European. A virtuosic work far ahead of its time, it paved the way for laryngeal theory and may have stimulated Saussure's later development of structuralism.