How to get backlinks to my site?

hi
how do you know they arent showing ?

I have 120 backlinks according to Bing, but 0 according to Google. Since Penguin all of my sites have hit rock bottom, I wonder if backlinks arent showing if this hashad any effect on my serps.
It takes I'm told several months for backlinks to show, but after 12 months my backlinks still arent showing.
I am told Bing webmaster tools is the best analysis