I have a multiple regression model e.g. y=x1+x2+e

Can I estimate the model by using the model in two ways by using same values of y and x1, but two different sets of values of x2 obtained from two different sources? I want to do it as both sources for x2 are not highly reliable, but that's I what could get. I want to include this methodology in my prospectus. If you know some peer reviewed paper doing it, let me know. Thanks a lot!

tal