how do I fix a 1960's style kitchen wall unit to the wall?

[Julie]

I have a couple of 1960's style glass fronted kitchen wall units that I'd like to fix to the wall. They had no wall fixings attached when I acquired them. They aren't very heavy themselves but I'd like to display china and glass in them. What type of fixing/bracket should I use to attach these to the wall that would be both suitable to bear the load and also not look unsightly? The cabinets are wooden but the back panel looks to be a fairly lightweight chipboard. The strongest part of them looks to be the frame which is made of approx 1 inch wooden battens. I'm attaching them to an external wall that's brick and plaster.