Causes of language change. In Luraghi & Bubenik eds, Continuum Companion to Historical Linguistics. London/New York, Continuum, 2010, 354-366 Silvia Luraghi

https://www.academia.edu/20133253/Causes_of_language_change_In_Luraghi_and_Bubenik_eds_Continuum_Companion_to_Historical_Linguistics_London_New_York_Continuum_2010_354_366