Laotongguan Chinese hamburger is a major feature of Shaanxi, which has a long history and cultural heritage. It is very famous and popular in Guanzhong area. I think you'd better study in Shaanxi. You can see it in many places in xi 'an, Shaanxi. If you want to learn, you can go to the store or go to a place that specializes in training snacks. I know Guan Xiangxing's train snacks in Ann, and the people who always see trolleys selling things in the night market are all from their school.