Tasqeeruddin, S., and P.K. Dubey. “A Facile and Efficient Synthesis of 3-(1H-Benzimidazol-2-yl)chromen-2-Ones”.
Asian Journal of Chemistry
, vol. 23, no. 7, Mar. 2011, pp. 3297-8, https://asianpubs.org/index.php/ajchem/article/view/10589.