References
Steven E. Boër
Propositional attitudes and formal ontology
1994
Synthese 98/2
Chisholm on intentionality, thought, and reference
1986
in: Roderick M. Chisholm, Dordrecht : Springer
Substance and kind: reflections on the new theory of reference
1985
in: Analytical philosophy in comparative perspective, Dordrecht : Springer