As always, both Introduction to Language (Rodman, Fromkin, and Hyams) and Language Files (Ohio State University Press) have a long list of resources. But for this chapter, I consulted a wide variety.
To start off, the Wikipedia pages on grammatical mood and grammatical aspect have very good information, and the references they list are outstanding. They are regularly updated with the latest research in the field, and are great starting points.
The other texts that were consulted are considered 'handbooks' of semantics and pragmatics--if you take an upper division or graduate course in semantics or pragmatics, you will often have these are course materials and/or reference materials:
- Allwood, Jess, Lars-Gunnar Andersson, and Osten Dahl. 2012. Logic in Lingusitics. Cambridge University Press;
- Comrie, Bernard. 1995. Aspect. Cambridge University Press;
- Comrie, Bernard. 2012. Tense. Cambridge University Press;
- Levinson, Stephen C. 2014. Pragmatics. Cambridge University Press; and,
- Palmer, F.P. 2012. Mood and Modality. Cambridge University Press.