Use of contraceptive methods and risk of unwanted pregnancy in Spanish women aged 40-50 years: Results of a survey conducted in Spain

1. Lete, I.
2. Bermejo, R.
3. Parrilla, J.J.
4. Dueñas, J.L.
5. Coll, C.
6. Serrano, I.
7. Doval, J.L.
8. Martínez-Salmén, J.