2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41782We summarize three alternative extensions of the quark-valence picture of nucleon strangeness and spin, including (1) gluon spin in QCD, (2) Bjorken sum rule and QCD, (3) D--E meson mixing and tadpole leakage. All three approaches suggest that ~40% of the nucleon's spin (as well as its momentum) resides with quarks, but that less than 6% is due to strange quarks.Accepted for publication in special issue of Hadronic JournalHigh Energy Physics - Phenomenologytext