Willetts, M.C. (2016). Domestic partnerships in the United States. In C.L. Shehan (Ed.)., Encyclopedia of Family Studies.
Willetts, M.C. (2010). Domestic partnerships. In M. Shally-Jensen (Ed.), Encyclopedia of Contemporary American Social Issues, pp. 891-899. Santa Barbara, CA: ABC-CLIO, LLC.
Willetts, M.C. (2022). Convictions and penalties among rescue and non-rescue non-human animal hoarders. Society & Animals. doi:10.1163/15685306-bja10070
Warner, C., & Willetts, M.C. (2021). Protecting companion animals from domestic
abuse: A comparative analysis of legal developments in the U.S. and the U.K. Global Journal of Animal Law 9. http://ojs.abo.fi/ojs/index.php/gjal/article/view/1724
Willetts, M.C. (2020). An exploratory investigation of companion animal custody disputes following divorce. Journal of Divorce and Remarriage. DOI: 10.1080/10502556.2020.1830258
Willetts, M.C. , & Beck, F.D. (2020). The influences of Buddhism and development on the well-being of Bhutan's street dogs. Animal Studies Journal 9 (2), 56-86. https://ro.uow.edu.au/asj/vol9/iss2/4
Cook, M., & Willetts, M.C. (2019). Affiliations for homeless individuals through social enterprise employment. The Social Enterprise Journal, 15(2), 215-232.
Sprecher, S., O'Sullivan, L.F., Drouin, M., Verette-Lindenbaum, J., & Willetts, M.C. (2019). The significance of sexual debut in women's lives. Current Sexual Health Reports 11, 265-273.
Willetts, M.C. (2017). "Combating Speciesism: Is an Immersion Experience with Non-Human Animals an Effective Strategy?" Society & Animals 25(5): 456-474.
Willetts, M.C. (2003). An exploratory investigation of heterosexual licensed domestic partners. Journal of Marriage and Family, 65(4), 939-952.