The Swadesh wordlists for eight East Central Khoisan languages. The main data source is Vossen 1997, except for Hietshware where the source is Dornan 1917. See the ECK etymological database for details on bibliography, transcription, and cognation issues.
NB: most of the wordlists are incomplete and the selection of etyma is occasionally questionable, since no detailed dictionaries of the languages as such are available (Vossen 1997 is essentially a short etymological dictionary). Considering that the languages are quite closely related, the incompleteness may seriously impact the classification results. Nevertheless, the genealogical tree more or less matches Vossen's original classification. The only issue is with Tsixa, for which serious evidence exists that it may actually be a West rather than East Central Khoisan idiom; whether the current lexicostatistical placing of it is correct can only be determined by future research on the language.