, 1992, 'Trouble in paradise?: on the alleged incoherence of the Tractatus', Grazer Philosophische Studien 42, 23-55.
, 1990a, What objects could not be, in R. Haller & J. L. Brandl (eds.), Wittgenstein — eine neubewertung/Wittgenstein — towards a re-evaluation, Dordrecht, Springer, pp. 51-63.