Williams %R (WILLR)

Interpretation / Algorithm
Technical Analysis Studies [prophet.net]
Description with math formula [FMLabs.com]
Technical Analysis A to Z by Steven B. Achelis [equis.com]

Product Implementation	Function / Formula / Script / Source Code
Genius Trader [geniustrader.org]	PERL Script - GT::Indicators::WilliamsR [geniustrader.org]
TA-Lib [ta-lib.org]	C/C++ Source Code - TA_WILLR()
Wealth-Lab [wealth-lab.com]	ChartScripts using WilliamsR [wealth-lab.com]