Rodriguez-Rojo, Maria del Pilar, Daniel Sánchez-Mata, Salvador Rivas-Martínez, e Michael G. Barbour. 2001. «Syntaxonomical approach for classification of the Californian serpentine annual grasslands». Lazaroa 22 (janeiro): 83-94. https://revistas.ucm.es/index.php/LAZA/article/view/LAZA0101110083A.