There's no way you can be sure from looking at photos. I went on ebay and saw a signature from Zyuzin when he was with Tampa, Minny and Calgary and they all look a bit different. I do think it's him though. The A he signs looks like a J in all of them.
http://64.202.180.6/pcmauctions/dec2...otImg17894.jpg
It's definitely not Ference. His signature looks like a Chinese letter.
http://cgi.ebay.ca/CALGARY-FLAMES-AN...ayphotohosting