If you are more people who would like to share references, one group member creates the group library and give access to the rest of the group.
All group members need to have a zotero profile.
1. Log in to zotero.org with your username and password
2. Choose "Groups" and "Create a New Group":
3. Type a group name and choose "Private Membership"
4. In "Memers Settings" you can invite people to join the group.
Use e-mails affiliated with zotero accounts:
6. When the group members has accepted the invitation change the role of the group member to "Admin" in "Member Settings". When the role has been change the group members can add content to your shared folders:
7. The collections which you share with others are visible below your private collections in your zotero library: