Lexikon der indogermanischen Partikeln und Pronominalstämme

The Lexikon der indogermanischen Partikeln und Pronominalstämme (LIPP, "Lexicon of the Indo-European Particles and Pronominal Stems") is an etymological dictionary of the Proto-Indo-European (PIE) particles and pronouns, published in 2014. It consists of two volumes; number 1 containing an introduction, terminology, sound laws, adverbial endings, nominal suffixes, appendices, and indices, and number 2 containing the lexicon.