, 2019, 'Second-order logic: properties, semantics, and existential commitments', Synthese 196 (7), 2643-2669.
, 2012, 'What is absolute necessity?', Philosophia Scientiae 16 (2), 117-148.
, 2011, The problem of mathematical objects, in G. Sommaruga (ed.), Foundational theories of classical and constructive mathematics, Dordrecht, Springer, pp. 71-84.
, 2010, 'The bearable lightness of being', Axiomathes 20 (4), 399-422.
with Wright, C. , 2009, 'Focus restored: comments on John MacFarlane', Synthese 170 (3), 457-482.
, 2006, 'The limits of abstraction', Philosophy and Phenomenological Research 72 (1), 223-232.
, 2005, 'Real numbers and set theory – extending the neo-Fregean programme beyond arithmetic', Synthese 147 (1), 21-41.
, 2002, 'Can arboreal knotwork help Blackburn out of Frege's abyss?', Philosophy and Phenomenological Research 65 (1), 144-149.
, 1990a, Nominalism, in A. D. Irvine (ed.), Physicalism in mathematics, Dordrecht, Springer, pp. 121-144.