Literature review
Guide
http://www.library.illinois.edu/bix/pdf/genguide/searchtips.pdf
Keyword development
https://www.powerthesaurus.org
Reference extraction
http://labs.crossref.org/pdfextract/
Datasets
www.ukdataservice.ac.uk – datasets (registration required) from cohorts
Data.gov & healthdata.gov – US datasets, most of which are publicly available
http://www.mortality.org – The human mortality database
www.kdnuggets.com/datasets/index.html – includes some health-related resources
Text analysis
http://www.tapor.ca/ – directory
http://textometrie.ens-lyon.fr/ – TXM free
https://gate.ac.uk/ – open source
Data analysis/Statistics
JASP – https://jasp-stats.org/
SOFA – http://www.sofastatistics.com/home.php – advertised as user-friendly