Artíñano, Begoña, Pedro Salvador, y Manuel Pujadas. «Study of atmospheric pollution by particulated matter in Madrid (I): source apportionment». Física de la Tierra, vol. 21, vol. 21, 2010, pp. 41-49, https://revistas.ucm.es/index.php/FITE/article/view/FITE0909110041A.