The proven Zacks Rank system focuses on earnings estimates and estimate revisions to find winning stocks. Nevertheless, we know that our readers all have their own perspectives, so we are always looking at the latest trends in value, growth, and momentum to find strong picks.Considering these trends, value investing is clearly one of the most preferred ways to find strong stocks in any type of market. Value investors rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.Zacks has developed the innovative Style Scores system to highlight stocks with specific traits. For example, value investors will be interested in stocks with great grades in the "Value" category. When paired with a high Zacks Rank, "A" grades in the Value category are among the strongest value stocks on the market today.One company to watch right now is Amer Movil (AMX). AMX is currently holding a Zacks Rank of #1 (Strong Buy) and a Value grade of A.Value investors also use the P/S ratio. The P/S ratio is is calculated as price divided by sales. This is a prefered metric because revenue can't really be manipulated, so sales are often a truer performance indicator. AMX has a P/S ratio of 0.79. This compares to its industry's average P/S of 1.21.Finally, investors should note that AMX has a P/CF ratio of 4.24. This metric takes into account a company's operating cash flow and can be used to find stocks that are undervalued based on their solid cash outlook. This stock's P/CF looks attractive against its industry's average P/CF of 6.75. Over the past year, AMX's P/CF has been as high as 5.08 and as low as 3.16, with a median of 4.49.Value investors will likely look at more than just these metrics, but the above data helps show that Amer Movil is likely undervalued currently. And when considering the strength of its earnings outlook, AMX sticks out at as one of the market's strongest value stocks.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report America Movil, S.A.B. de C.V. (AMX): Free Stock Analysis Report To read this article on Zacks.com click here.