Mari, is your Google Docs account separate from your private accounts? If not, then open another account and close that one but before doing so have you checked the verified users in the "Account verification" post?
Whoever finds a friend, finds a treasure. / Chi trova un amico, trova un tesoro!
When you share the document there is a check box so those you share with can't on-share:
It is circled in the screenshot above. I am not sure how secure it is as google docs are new to me. That may help for future documents.
For the time being, you could create another, temporary, gmail and transfer the documents there (deleting them from your other address) and ask for those who were translating them to pm you their emails - then you would have a permanent list you could refer to. A pain, I know, but that is the only thing I can think of. Maybe Jo knows the machinations of google docs better than I do.
“Remember: Enjoy your life today, because yesterday has gone and tomorrow may never come.”