Ikea Bracket Style - Anywhere else you can get these?

Hi,

I'm building 2 alcove units, and I want to fit them to a back wall taking advantage of the play these brackets allow. Every time I drill masonry I hit a mortar joint and have to re-drill.

Does anyone know where you can buy these brackets from? I know them from Ikea units, but I think Hafele also make them. The only place I can find them is...

Ikea Bracket Style - Anywhere else you can get these?