Article Synopsis on Traders.com http://technical.traders.com/archive/archivelogin.asp?file=\V12\C01\SMOOTHI.pdf&src=SC
Traders.com January 1994 Archive http://technical.traders.com/archive/volume-2014.asp?yr=1994#Jan
Formula at ETF HQ http://etfhq.com/blog/2010/11/17/double-and-triple-exponential-moving-average/
Formula at MetaTrader 5 http://www.metatrader5.com/en/terminal/help/analytics/indicators/trend_indicators/dema
Formula at Trading Technologies https://www.tradingtechnologies.com/help/xstudy/double-exponential-moving-average-dema/