Collectanea mathematica Volume 75 Issue 2 Issue 1 Volume 74 Issue 3 Issue 2 Issue 1 Volume 73 Issue 1 Volume 72 Issue 3 Issue 2 Issue 1 Volume 71 Issue 3 Issue 2 Issue 1 Volume 70 Issue 3 Issue 2 Issue 1 Volume 69 Issue 3 Issue 2 Issue 1 Volume 68 Issue 3 Issue 2 Issue 1 Volume 67 Issue 3 Issue 2 Issue 1 Volume 66 Issue 3 Issue 2 Issue 1 Volume 65 Issue 3 Issue 2 Issue 1 Volume 64 Issue 3 Issue 2 Issue 1 Volume 63 Issue 3 Issue 2 Issue 1 Volume 62 Issue 3 Issue 2 Issue 1