Reference managers

Reference mangers make it easy to organize and format citations.   They can assist with managing citations, pdfs and image file by organizing important documents by subject and allowing you to search using keywords. Add and orgainse any papers that are relevant to your research as you read them. This will hep you remember to appropriately cite articles that yo have read. 

Some widely used reference management and formatting software applications are:

BibTeX
EndNote
Mendeley
Papers
RefWords
Zotero
ReadCube

source: Springer.com