Qiqqa
Mendeley
Zotero
JabRef
Citavi
Docear
Paperpile
BibDesk
Urkund
iThenticate
Turnitin
PlagScan
Plagramme
Unicheck
AntiPlagiarist
Plagiarisma
Qiqqa UrkundQiqqa is by far the strongest solution for research and managing pdf's. Zotero, named as a comparison is weak as it does not allow pdf;s to be loaded into its interface - you need to use a pdf reader, which defeats its whole purpose. With Qiqqa documents in a library can be searched together. It has excellent maps of your libraries. It is not prefect, having a few glitches, but still is the only one of its kind.
Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
iThenticate - Prevent Plagiarism in Published Works
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Turnitin - Turnitin is preferred by educational institutions around the world for preventing plagiarism. Instructors at all levels of education can request that students use the service to submit papers, and Turnitin checks those papers for plagiarism.
JabRef - Graphical Java application for managing bibtex (. bib) databases.JabRef · JabRef Help · JabRef | Blog · OpenOffice/LibreOffice .
PlagScan - The Internet makes plagiarism a bigger problem than ever.