I tried using Zotero on scientific journal sites such as PLOS, Nature,Science, Elsevier’s Science Direct and it works perfectly. I have tried all their claimed features and they work seamlessly. When compared to commercial equivalents like Endnote and R
Zotero [zoh-TAIR-oh] is a free, easy-to-use Firefox extension to help you collect, manage, and cite your research sources. It lives right where you do your work — in the web browser itself. Features Automatic capture of citation information from
P. Siehndel, R. Kawase, A. Hadgu, and E. Herder. Proceedings of the 22Nd International Conference on World Wide Web Companion, page 425--430. Republic and Canton of Geneva, Switzerland, International World Wide Web Conferences Steering Committee, (2013)