1. Adger, David, and Gillian Ramchand. 2003. Predication and equation. Linguistic Inquiry 34(3): 325–359.
2. Aloni, Maria, and Floris Roelofsen. 2011. Interpreting concealed questions. Linguistics and Philosophy 34: 443–478.
3. Baker, C. L. 1968. Indirect questions in English. Ph.D. diss., University of Illinois, Urbana-Champaign.
4. Barros, Matthew. 2016. Specification as an inter-taxonomic phenomenon. Ms., Yale University. http://ling.auf.net/lingbuzz/repo/semanticsArchive/article/001575.
5. Caponigro, Ivano, and Daphna Heller. 2007. The non-concealed nature of free relatives: Implications for connectivity in specificational sentences. In Direct compositionality, eds. Chris Barker and Pauline Jacobson, 237–263. Oxford: Oxford University Press.