Need a paperwork from you

Now I, Yan Yang am an American citizen but husband (Jianbo Wu) works and is Chinese. We plan to buy an apartment in China and to issue both our names in the title. But the titel company and the bank need need a paperwork from you guys to identify this relationship or the truth of my status. If you could help do this, what kind of documents you need. So I can fax them to you. Many thanks.
Yan Yang
573-529-5382 cell
573-228-9561 home
address: 4707 GLenn Wesley Ct.
Columbia Mo, 65203