Wille, Alvaro. “A Comparative Study of the Pollen Press and Nearby Structures in the Bees of the Family Apidae”. Revista de Biología Tropical 27, no. 2 (December 1, 1979): 217–221. Accessed November 25, 2024. https://revistas.ucr.ac.cr/index.php/rbt/article/view/25651.