Chen's group did an excellent job to get my NIW I-140 approved. It was beyond my expectation because my I-140 was approved in 95 days which is pretty soon after Matter of Dhanasar. I was referred by my friend. First I thought my profile is a little bit weak and I wanted to wait for one more year to strengthen my profile in term of publications and citations. However, Chen's group gave me a "Approval of Refund" service after I sent them my resume. I could not believe and asked them again if I could get approved with my current credentials. They said YES. Well, I went ahead and started working with Chen's group since then. They will have their own strategies to get your I-140 approved. I am very happy working with them. Highly recommended.