Here is the link.
The easiest thing to do is to buy a stock. The difficult thing to do is to know when to sell. Selling stocks is always tricky because a stock can always go up just after you sold it. The first discussed strategy, that looks towards fundamental indicators and uses fundamental analysis certainly helps in avoiding selling too early or too late. Another strategy is portfolio rebalancing that makes things much easier as you have to mechanically sell when something appreciates. The third strategy involves buying something much better, i.e. 50% better than the other portfolio holding. A better investing opportunity can always arise but you shouldn't trade too much around it. The fourth strategy is about using a stop loss. I discuss the pros and cons of using a stop loss. the fifth is not so much a strategy as the reaching of a goal, when you did it, sell your stocks and enjoy your life.