Yippy!
Organizes search results

WolframAlpha
Math and data search engine.

DuckDuckGo
Non-tracking search engine.



ACADEMIC SEARCH ENGINES
Educational Technology and Mobile Learning (July 8, 2014)
6 Good Academic Search Engines for Science Teachers

Educational Technology and Mobile Learning (February 2013?)
12 Fabulous Academic Search Englines

te@chthought (November 24, 2012)
100 Search Engines for Academic Research
Check out these suggestions for every category including general research, science, math, social sciences, etc.