Thanks for the feedback! Now that we’ve done this with Mendeley, Zotero is next in line (but there are other things we will need to finish first). In the mean time, the best workaround I can offer is to use Mendeley or Citeulike.Raphael Schiedung commented
This would be a great feature! I was expecting this feature when I proposed Overleaf for the collaborative writing of our paper and was very disappointed when I realized that it is not possible to collaboratively edit the bibliography.