Export articles into RIS or Bibtex format

Hi. I need to do a batch export of OJS articles into a RIS or Bibtex format.
From how I see it, there is not a custom OJS plugin for that.
Does anybody know a workaround to accomplish that? Maybe some plugin or app that converts OJS exported native XML or Pubmed xml to any of those formats???

Right now the only option I was able to find is to manually import each article into a RIS format using Zotero Chrome plugin… At least it imports basic tags but is very painful to go through all issues doing it manually…

Any help will be appreciated!