Where can I find the SQL-89 standard?
This one looks like the document you are after (although French, not English, and not free)
https://iteh.it/catalog/standards/iso/7c7fa915-f99f-4ce9-8aa4-0e896d89ed84/iso-iec-9075-1989
Or this one seems to have English and Russian versions:
https://gostperevod.com/st-iso-iec-9075-1989.html