Zotero is a citation management tool built into your web browser -- Firefox or Chrome -- that helps you collect, organize, and share citations. Zotero also helps you create and format bibliographies and footnotes in a wide variety of citation styles (Chicago, MLA, APA, etc.) for your papers and research projects. Zotero works on PCs, Macs, and Linux systems, and is compatible with MS Office, Google Docs, and Open Office. Zotero is freely available for download from www.zotero.org.
Box and Google Drive are available for free to University of Chicago users. Dropbox also offers free storage to users. Google Drive, Box and Dropbox offer similar features with key differences. Below are some of them.
More information about key differences between Google Drive and Box