Chen E, Looman M, Laouri M, Gallagher M, Van Nuys K, Lakdawalla D, Fortuny J. Burden of illness of diabetic macular edema: literature review. Curr Med Res Opin. 2010 Jul;26(7):1587-97. doi: 10.1185/03007995.2010.482503 PMID 20429823
Astier P, Arana A, Oterino D, Lopez MA, Piero S. Cost analysis for the different strategies in cataract surgery. Presented at the V Congreso de la Sociedad Española de Salud Pública y Administración Sanitaria; 1993. Granada, Spain.