Books on Amazon:
Reference/Consciousness/Chalmers: if we can refer to our conscious experiences, our consciousness is probably not causally irrelevant to the explanation of consciousness. In any case not, if a causal relation is required for reference. However, this is not always necessary when it comes to e.g. intensions. E.g.
Primary Intension: For example, the largest star in the universe: picks out a star in any given centered world, whether I have a causal relationship with it or not. Certainly, however, it is usually the case that, in the centered world, objects are picked out by a causally induced reference. But that does not always have to be the case.
Causality: may often be helpful to distinguish between potential candidates of the reference, or to learn concepts. (Language acquisition).
The Conscious Mind Oxford New York 1996
Constructing the World Oxford 2014