Konrad Völkel#Fabien Morel
Is it possible to prove Serre's Problem (the Quillen-Suslin theorem) via Motivic Homotopy Theory?
Walk-through to Morel-Voevodsky A¹-homotopy theory, page 48-50
Categorical background for A¹-homotopy theory (simplicial model categories)
Walk-through to Morel-Voevodsky A¹-homotopy theory part II (page 48, Lemma 1.1)