Here at Zacks, we focus on our proven ranking system, which places an emphasis on earnings estimates and estimate revisions, to find winning stocks. But we also understand that investors develop their own strategies, so we are constantly looking at the latest trends in value, growth, and momentum to find strong companies for our readers.Of these, perhaps no stock market trend is more popular than value investing, which is a strategy that has proven to be successful in all sorts of market environments. Value investors rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.Luckily, Zacks has developed its own Style Scores system in an effort to find stocks with specific traits. Value investors will be interested in the system's "Value" category. Stocks with both "A" grades in the Value category and high Zacks Ranks are among the strongest value stocks on the market right now.One stock to keep an eye on is Unicom (CHU). CHU is currently sporting a Zacks Rank of #2 (Buy) and an A for Value. The stock is trading with P/E ratio of 9.28 right now. For comparison, its industry sports an average P/E of 10.79. Over the past 52 weeks, CHU's Forward P/E has been as high as 15.06 and as low as 8.14, with a median of 10.52.We also note that CHU holds a PEG ratio of 0.82. This popular figure is similar to the widely-used P/E ratio, but the PEG ratio also considers a company's expected EPS growth rate. CHU's PEG compares to its industry's average PEG of 0.95. Within the past year, CHU's PEG has been as high as 1.10 and as low as 0.72, with a median of 0.88.Value investors will likely look at more than just these metrics, but the above data helps show that Unicom is likely undervalued currently. And when considering the strength of its earnings outlook, CHU 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 China Unicom Hong Kong Ltd (CHU): Free Stock Analysis Report To read this article on Zacks.com click here.