What I was asking was not duplicate contacts but how to back-up contacts which I have merged in my mobile phone. One contact is for example connected now with google+, hexsync, facebook and with google contact.... So how to backup these connections so I can have it there after factory reset?
Again example one of my contact share information/is merged with these services:
facebook (photo and real name, email address etc)
hexsync (hd photo)
google+ (work number and some other info)
google email account (actual phone number and nickname)
So one contact is connected into one multiple services information hub in my contact list on my phone so how can I backup this?