Grüninger, W. and Monge-Nájera, J. (1988) “Use of the temperate lichen <i>Hypogymnia physodes</i> (Parmeliaceae) to evaluate air pollution in the Tropics”, Revista de Biología Tropical, 36(2B), pp. 545–547. Available at: https://revistas.ucr.ac.cr/index.php/rbt/article/view/23895 (Accessed: 5May2024).