Lusha is a continuously updating database that provides B2B Salespeople with targeted, accurate, and timely business information. Lusha aggregates its data from multiple sources, cross-checking and updating LIVE to ensure up-to-the-minute data accuracy and database cleanliness.
Qiqqa 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.
Hunter - Find all the email addresses related to a domain
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Apollo.io - Apollo’s predictive prospecting, sales engagement, and actionable analytics help the teams to reach its full revenue potential.
JabRef - Graphical Java application for managing bibtex (. bib) databases.JabRef · JabRef Help · JabRef | Blog · OpenOffice/LibreOffice .
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.