Sentinel surveillance of HIV infection in HIV test clinics, Spain 1992-2002 Barrasa, A and Castilla, J and del Romero, J and Pueyo, I and de Armas, C and Varela, J A and Ureña, J M and Bru, F J and Ordoñana, J R and Sáez de Vicuña, L M and and the EPI-VIH Group, Eurosurveillance, 9, 466 (2004), https://doi.org/10.2807/esm.09.05.00466-en