Google Scholar - Google Scholar is a freely accessible web search engine that indexes the full text of scholarly...
SemanticScholar - An academic search engine that utilizes artificial intelligence methods to provide highly relevant results and novel tools to filter them with ease.
ResearchGate - Access scientific knowledge, and make your research visible
Refseek - Refseek is a best in class academic search engine tool for students and researchers to extract the relevant information across the internet.
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Biohunter - Biohunter is a one-stop portal for literature search, batch-download PDFs and reference manager