Trading with Gann lines by David Lamarr
Gann lines, although only a small part of W. D. Gann's methods, provide an effective, straightforward way of determining support and resistance areas and times when to expect a change in trend. They can be thought of as "price/time" trendlines vs. the standard price-only trendlines many technical analysts use.
Gann strongly believed time was the major factor in determining when a change of trend could be expected. These Gann lines project the market's natural rhythm on a price chart and have a distinct advantage over price trendlines by providing assistance in anticipating market moves vs. a price-following system, such as trendlines.