Can't remember how old your children are but I recently helped some people who approached me as NCT newsletter ed to set up German and French speaking parent and child groups in Nottingham.
They put up notices at the Nearly New Sale which attracted a few people in and, because I had various contacts I had made through NCT - in my classes and doing baby-related stuff - I was able to put them in touch with more and with each other and with another group in the area.
The nature of the beast is that people who aren't local tend to go to NCT classes to meet other people. I've only taught 17 couples so far and I've had German, French and Dutch people in my classes so might be worth using that.
Not sure what publications there are - I think there's an Active Kids thing that goes out to local libraries and some schools that might be worth a try.