2Dixon, R. M.W. (1982) Where Have All the Adjectives Gone? Berlin: Mouton.
3Dixon, R. M.W. (2004) Adjective classes in typological perspective. In R. M. W. Dixon & A. Y. Aikhenvald ( eds. ), Adjective Classes, 1 - 49. Oxford : Oxford University Press.
4Pustet, R. (2003) Copulas. Oxford: Oxford University Press.