Impact of the Spanish Smoking Law on Exposure to Second-Hand Smoke and Respiratory Health in Hospitality Workers: A Cohort Study. - Fernández, Esteve; Fu, Marcela; Pascual, José A.; López, María J.; Pérez-Ríos, Mónica; Schiaffino, Anna; Martínez-Sánchez, Jose M.; Ariza, Carles; Saltó, Esteve; Nebot, Manel (PLoS ONE, 2009)