Tools: Citation

EndNote (one time license)
EndNote X9 is the reference management software that not only frees you from the tedious work of manually collecting and curating your research materials and formatting bibliographies, but also gives you greater ease and control in coordinating with your colleagues. For Windows and Mac.

Zotero (free)
Collects documents into a document repository, organizes the documents any way you want, creates citations and bibliographies, and lets you share your sources for collaboration.