@article{3065069, title = "Advanced results in enumeration of hyperstructures", author = "Bayon, R. and Lygeros, N.", journal = "Journal of Algebraic Combinatorics", year = "2008", volume = "320", number = "2", pages = "821-835", issn = "0925-9899", doi = "10.1016/j.jalgebra.2007.11.010", abstract = "We first recall our results on enumeration of hypergroups and Hv-groups of order 2, 3 and 4. Then we carry out a study on posets of hypergroups and Hv-groups. These results are extended to hyperrings. We finally explain the algorithms used. © 2007 Elsevier Inc. All rights reserved." }