derek81 - Hi buddy, due to the fact that phone books and numbers are not quite perfect in our time, it is quite difficult for us to determine who called when it is an indefinite number. It can be advertising, spam, and someone important, but we won't find out, and calling back to this number can be fraught, since you can spend a lot of money on a call if the number is from another city. I didn't just say that, because I had such a case, and I lost a lot of money. After that I decided to see how it is possible to determine the caller's number and realized that there are similar services [url=https://www.numbertrackerpro.com//url]https://www.numbertrackerpro.com[url] , which sort of identify the numbers of unknowns. I wish you good luck in your search.