I only know the residential address, how to find contact information!

The problem you are talking about is actually an economic accounting problem of finding people, that is, how to get the telephone number of the address inventor in the cheapest, most labor-saving and most economical way. The cost of writing a letter to call him back is 1.2 yuan money. Let's talk and think. Is there a more time-saving and labor-saving method than 1.2 yuan money? Investigating companies? Or go to 1 14? Not everyone's phone number is public? Even if you make a phone call, a phone call will definitely not solve the problem, often to save energy, but you will get nothing after a long time. So, don't bother to find a shortcut. Write a letter!