In print:
CRC HANDBOOK OF CHEMISTRY and PHYSICS
(Shelved on the Science Index Table)
Online:
ASTRO-PHYSICAL
DATA
FREE Internet site <http://www.physlink.com/Reference/AstroPhysical.cfm>
ATOMIC CLOCK
FREE Internet site <http://www.time.gov>
Official U. S. Time
ATOMIC
SPECTROSCOPIC DATABASE
FREE Internet site <http://physics.nist.gov/PhysRefData/ASD1/choice.html?>
NIST PHYSICAL REFERENCE
DATA
The National Institute of Standards and Technology (NIST)
FREE Internet site <http://physics.nist.gov/PhysRefData/
THERMODEX
FREE Internet site <http://thermodex.lib.utexas.edu>