A single-center, randomized, doubleblind, placebo-controlled study of interferon beta- I b on primary progressive and transitional multiple sclerosis

1. Montalban, X.
2. Sastre-Garriga, J.
3. Tintoré, M.
4. Brieva, L.
5. Aymerich, F.X.
6. Río, J.
7. Porcel, J.
8. Borràs, C.
9. Nos, C.
10. Rovira, À.