The databases you described are all professional databases, and only those search institutions have them. Such as university libraries, city libraries, etc. What you said about querying People's Daily 1966 May 1 can be found in some schools that have purchased the People's Daily database. I remember that the library of China Geo University seems to have /page.php? cid = 282 & ampaid= 1548

But you need the school's IP to use it