Hi @dianvincensia,
Thank you for clarifying. I’m not sure what exactly would lead to Google Scholar indexing your material, but my guess is that it was publicly exposed in some fashion (i.e. available on the web), and that the Google Scholar indexing crawl picked it up as a part of its indexing efforts, since you are using a recognized platform. That said, getting one’s material removed from Google Scholar’s index has proven to be difficult, and is something, unfortunately, that we have little control of it. This post has some good advice (although it’s for OJS and not OCS): How to remove a journal from Google (Scholar) - #12 by bernieh - and other community members may wish to weigh in with advice as well.
-Roger
PKP Team