Abstract Perturbative cross-sections in QCD are beset by logarithms of kinematic invariants. whose arguments vanish when heavy particles are produced near threshold. Contributions of this type often need to be summed to all orders in the coupling. in order to improve the behaviour of the perturbative expansion. https://www.bekindtopets.com/limited-stock-Bovi-Shield-Gold-FP-5-L5-HB-best-super/