We give a short proof of the \(L^{1}\) criterion for Beurling generalized integers to have a positive asymptotic density. We actually prove the existence of density under a weaker hypothesis. We also discuss related sufficient conditions for the estimate \(m(x)=\sum_{n_{k}\leq x} \mu(n_k)/n_k=o(1)\), with \(\mu\) the Beurling analog of the Moebius function.