МuzychukG.М., and ProkopchukV.М. “World Assortment of Cultivars of Flower Ornamental Plants of Scrophulariaceae Juss. Family and Perspectives for Their Introduction into Ukraine”. Plant Introduction 25 (March 1, 2005): 46-52. Accessed July 8, 2024. http://plantintroduction.org/index.php/pi/article/view/393.