What are the five schools of guzheng?

There are about nine schools of guzheng in China, they are: Mongolian zheng, Korean zheng, Shandong zheng, Hakka zheng, Jianjiang zheng, Henan zheng, Qin zheng, Min zheng and Chaozhou zheng. There are five zheng schools which have a long history and are more important, they are: Henan zheng school, Shandong zheng school, Zhejiang zheng school, Hakka zheng school and Chaozhou zheng school.