Have you done high quality back-linking before? If so what sites do you use?

Have you done high-quality back-linking before? If so what sites do you use? 

Answer: Yes, I have done some high PR back-linking in my previous works and I proudly say that I have ranked multiple sites. To check if I’m telling the truth or not, you can check my employment history and portfolio is given below (It would be better if you can include some links here)