2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47915I will briefly review the progress which has been made in the investigation of secondary heavy quark production at LEP. I will show why a calculation of the secondary heavy quark multiplicity, keeping the dependence on an event shape variable, is essential for better exploitation of data, and I will present the results of such a calculation. This will be compared to Monte Carlo studies.6 pages, uses moriond.sty (included), Contribution to The XXXIst Rencontres de Moriond, "QCD and High Energy Hadronic Interactions", Moriond, Les Arcs, March 21-28High Energy Physics - Phenomenologytext