ROMANIAN REPORTS IN PHYSICS Volume 61 Issue 1 Volume 50 Issue 4 Issue 3 Issue 2 Issue 1 Volume 49 Issue 10 Issue 9 Issue 8 Issue 4 Issue 3 Issue 2 Issue 1 Volume 48 Issue 10 Issue 9 Issue 8 Issue 7 Issue 6 Issue 5 Issue 4 Issue 3 Issue 2 Issue 1 Volume 47 Issue 10 Issue 9 Issue 8 Issue 7 Issue 6 Issue 5 Issue 3 Issue 2 Issue 1