Influence of changes in physical activity on frequency of hospitalization in chronic obstructive pulmonary disease

1. Esteban, C.
2. Arostegui, I.
3. Aburto, M.
4. Moraza, J.
5. Quintana, J.M.
6. Aizpiri, S.
7. Basualdo, L.V.
8. Capelastegui, A.