Liu L, He A, Li X. Synthesis of Allantoin Catalyzed by SO42-/La2O3-SiO2-ZrO2. ajc [Internet]. 2012 Jan. 3 [cited 2024 Nov. 24];24(5):2298-300. Available from: https://asianpubs.org/index.php/ajchem/article/view/9004