@inproceedings{rogers-lambert-2019-classes, title = "Some classes of sets of structures definable without quantifiers", author = "Rogers, James and Lambert, Dakotah", editor = "de Groote, Philippe and Drewes, Frank and Penn, Gerald", booktitle = "Proceedings of the 16th Meeting on the Mathematics of Language", month = jul, year = "2019", address = "Toronto, Canada", publisher = "Association for Computational Linguistics", url = "https://preview.aclanthology.org/fix-sig-urls/W19-5706/", doi = "10.18653/v1/W19-5706", pages = "63--77" }