Physics and Science Reference by PhysLINK.com Save
Includes physical constants, online unit conversions, periodic table of elements, exact time, fundamental physical formulae and equations.
http://www.physlink.com/Reference/Ind...   

Astronomical Constants from NASA Save
Astronomical/space constants and equations.
http://www.ksc.nasa.gov/facts/faq04.html   

Beta-Theta Save
Gives general defintions, background and examples from the science fields of biology, physics, chemistry, math, and history. Includes forum boards.
http://www.beta-theta.com/   

EquationSheet.com Save
Searchable directory, arranged by field, of equations, constants, symbols and SI units. Also features LaTEX utilities, software links.
http://www.equationsheet.com/   

GrayLIT Network Save
Searchable database for reports that are generated by federally funded projects.
http://www.osti.gov/graylit/   

RefScout Save
A weekly, scientific reference mailing service. Screens databases covering life and medical sciences for the key words or the combination of key words specified and will automatically update with any abstract that has come up during the last seven days. Free service.
http://www.refscout.com/   

The Constants and Equations Pages Save
Expanding reference resource for science, math and astronomy
http://www.tcaep.co.uk/   

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