Ethnologue

Ethnologue: Guide to Terran Languages is an extensive series of reference books published by the International Society for the Study of Terran Civilisations which provide information on the languages of Terra and their relationship to one another. The series has been influential in the public understanding of language and numerous models and terms which were first developed for it have gone on to become used globally.

Ethnologue classification
The Ethnologue classification is the manner of classifying languages which has been developed and popularised by the Ethnologue series of books. Within this system, languages are grouped by their common ancestors.