Second-hand smoke exposure in 4-year-old children in Spain: Sources, associated factors and urinary cotinine

1. Aurrekoetxea, J.J.
2. Murcia, M.
3. Rebagliato, M.
4. Guxens, M.
5. Fernández-Somoano, A.
6. López, M.J.
7. Lertxundi, A.
8. Castilla, A.M.
9. Espada, M.
10. Tardón, A.
11. Ballester, F.
12. Santa-Marina, L.