Thrackles: An improved upper bound LNCS Fulek, Radoslav ; https://orcid.org/0000-0001-8485-1774 Pach, János A thrackle is a graph drawn in the plane so that every pair of its edges meet exactly once: either at a common end vertex or in a proper crossing. We prove that any thrackle of n vertices has at most 1.3984n edges. Quasi-thrackles are defined similarly, except that every pair of edges that do not share a vertex are allowed to cross an odd number of times. It is also shown that the maximum number of edges of a quasi-thrackle on n vertices is 3/2(n-1), and that this bound is best possible for infinitely many values of n. Springer 2018 info:eu-repo/semantics/conferenceObject doc-type:conferenceObject text http://purl.org/coar/resource_type/c_5794 https://research-explorer.ista.ac.at/record/433 Fulek R, Pach J. Thrackles: An improved upper bound. In: Vol 10692. Springer; 2018:160-166. doi:<a href="https://doi.org/10.1007/978-3-319-73915-1_14">10.1007/978-3-319-73915-1_14</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1007/978-3-319-73915-1_14 info:eu-repo/semantics/altIdentifier/arxiv/1708.08037 info:eu-repo/semantics/openAccess