Michener, Charles D. “An Interesting Method of Pollen Collecting by Bees from Flowers With Tubular Anthers”. Revista de Biología Tropical 10, no. 2 (December 1, 1962): 167–175. Accessed June 24, 2025. https://archivo.revistas.ucr.ac.cr/index.php/rbt/article/view/31044.