1. Beebe, J. R., & Sackris, D. (2016). Moral Objectivism across the lifespan. Philosophical Psychology, 29, 912–929.
2. Björkholm, S.. (2022). The duality of moral Language. On hybrid theories in metaethics. Dissertation, University of Stockholm.
3. Bordonaba Plou, D. (2017). Operadores de orden superior y predicados de gusto: Una aproximación expresivista. Dissertation, Universidad de Granada.
4. Camp, E. (2017). Metaethical expressivism. In T. McPherson & D. Plunkett (Eds.), The Routledge handbook of metaethics (pp. 87–101). Routledge.
5. Davies, M. (2008). The Corpus of Contemporary American English (COCA). Brigham Young University. https://www.english-corpora.org/coca/