http://oakroadsystems.com/math/loglaws.htm Ryan Hornschemeier
http://www.analyzemath.com/logfunction/logfunction.html xavier sullivan
http://www.algebralab.org/lessons/lesson.aspx?file=algebra_logarithmproperties.xml Bryce Chapman
http://abacus.bates.edu/acad/acad_support/msw/exps_and_logs.pdf Emily Martini
http://www.purplemath.com/modules/logrules.htm Tyler Mace
http://www.zweigmedia.com/RealWorld/calctopic1/logs.html Emma Claunch
http://www.algebralab.org/lessons/lesson.aspx?file=algebra_logarithmproperties.xml Tyler Mace
http://people.richland.edu/james/lecture/m116/logs/properties.html Emily Martini
http://www.5min.com/Video/How-to-Add-and-Subtract-Logarithms-516911144 Tyler Mace
http://www.brightstorm.com/math/precalculus/exponential-and-logarithmic-functions/properties-of-logarithms/ Logan Symmes