Ramazani, Ali, et al. “Synthesis of Highly Stabilized Phosphorus Ylides from Acetylenic Esters, CH-Acids and Triphenylphosphine in Aqueous Media”. Asian Journal of Chemistry, vol. 17, no. 1, Mar. 2016, pp. 297-00, https://asianpubs.org/index.php/ajchem/article/view/19765.