Useful Web Apps and Search Engines For Researches
100 Free and Useful Web Apps for Writer
http://www.onlineuniversities.com/blog/2010/03/100-free-and-useful-web-apps-for-writers/
100 Time-Saving Search Engines for Serious Scholars (Revised)
http://www.onlineuniversities.com/blog/2012/07/100-time-saving-search-engines-serious-scholars-revised/
100 Search Engines for Academic Research
http://www.teachthought.com/learning/100-search-engines-for-academic-research/
List of Academic Databases and Search Engines
https://en.m.wikipedia.org/wiki/List_of_academic_databases_and_search_engines
Ten Search Engines For Researches That Go Beyond Google
https://www.jisc.ac.uk/blog/ten-search-engines-for-researchers-that-go-beyond-google-11-jul-2013
