I'm trying to get a complete collection of the 'Abacus' books, but i'm missing a few, do any of you have any to swap with my 'doubles' ?
I have these:

so I have to swap:
1x number 2
2x number 3
1x number 13
and I need:
6
7
8
9
10
14 and 15, if these exist ?
can anyone help ?
