Petrographical composition and provenance of Neolithic Black stone artefacts in the collection of the Museum der Kulturen in Basel and in archaeological excavations near the shoreline of Lake Neuchâtel Switzerland - Diethelm, Inge (Non-flint raw material use in Prehistory. Old prejudices and new directions. L'utilisation préhistorique de matières premières lithiques alternatives. Anciens préjugés, nouvelles perspectives., 2009)