Gutiérrez R, E. P., L. del P. Rubí Ortíz, and O. Mayorga Pérez. “Seroprevalence of HIV/AIDS in Sex Workers and Drivers of Heavy Transport from the City of León”. UNIVERSITAS (LEÓN): SCIENTIFIC JOURNAL OF THE UNAN-LEÓN, vol. 2, no. 2, Nov. 2008, pp. 39-45, doi:10.5377/universitas.v2i2.1654.