You can also configure what roles you want to allow and which actions you want to restrict for a DocType. Go to the Article doctype, scroll down to the Permission Rules section, and add the roles.
You can also configure the type of action that is allowed for a particular role. Let's add a Librarian role that has permission for all actions and a Library Member role that has permission for Read action.
You can test this by creating a new User that has the Librarian role, and another User that has the Library Member role. Login with each user, and see what actions are allowed.