How to get all members of a campaign - REST Api

Hi,

I'm trying to get a list of all contacts that are in any of the steps a certain campaign.

I tried to use this: REST API - Accessing Contact Activities but for some reason the API returns nothing if I use "campaignMembership" as a type.

Moreover I think its unhandy to do 1.000s of requests to identify 10 members a campaign.

Any advice or suggestions greatly appreciated!

Thanks,

Simon