Wille, Alvaro. “Notes on the Morphology of the Musculature of the Salivary Syringe and Neck Region of Bees”. Revista de Biología Tropical 18, no. 1-2 (December 1, 1970): 33–51. Accessed June 30, 2025. https://archivo.revistas.ucr.ac.cr/index.php/rbt/article/view/28031.