Jackendoff, 1989 defines the conceptual semantics of natural language (distinguishing I-semantics from E-semantics). The research is directed towards finding relations between natural language structures. However, the I-semantics Jackendoff proposes builds conceptual definitions instead of taking the fundamental notion of a concept as an ability.
The reference to Steels, 1997 is rather complementary. Steels shows how artificial agents, instead of being programmed so, may learn to structure the world themselves.
Millikan, 2000 defines a concept as an ability to reidentify for a purpose, illustrates the difference between identification and classification, and has a chapter about concepts through language.