There is a national standard GB77 14-2005 on the Internet. You can find it. It's the authoritative standard. However, if you subscribe to a periodical, you need to mark it according to the requirements of the periodical. It doesn't matter if it is scattered, because if there are several from a document, a book or a piece of paper, you can mark them together. For example:

[1] [2] Yuan Yunkai, Cai Tiequan. Science curriculum and teaching theory [M]. Hangzhou: Zhejiang Education Press, 2003:9 13. Third class. Hope to be adopted!