Lei Y, Ding M, Yao Q. An Efficient One-Pot Synthesis of 4-Methyl Coumarins Mediated by melamine formaldehyde resin Supported Sulfuric Acid. ajomc [Internet]. 2017 Sep. 29 [cited 2024 Nov. 23];2(3):110-3. Available from: https://asianpubs.org/index.php/ajomc/article/view/15461