Dear Mr. Zhang and Mr. Bush,

I received my green card last week after almost 6-7 years of processing and filing applications. I would like to thank you both for taking me on in the beginning  and helping me file all the documentations for my green card process. I really appreciate all the work you have done and I have had a great experience with your firm over the past a few years. I will be sure to refer your firm to anyone who might need immigration services in the future. 

Thank you again!