The grades of three service stocks are on the rise this week on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

This week, Graham Holdings Co. (GHC) is making solid headway. The company’s rating improves to an A (“strong buy”) from last week’s B (“buy”) rating. Graham Holdings is a diversified education and media company whose principal operations include educational services, newspaper print and online publishing, television broadcasting and cable television systems. In Portfolio Grader’s specific subcategories of Earnings Growth, Cash Flow and Margin Growth, GHC also gets A’s. The stock has a dividend yield of 10.2%. For more information, get Portfolio Grader’s complete analysis of GHC stock.

This is a strong week for Cambium Learning Group, Inc. (ABCD). The company’s rating climbs to A from the previous week’s B. Cambium Learning Group provides intervention curricula, educational technologies, professional services, and other research-based education solutions in the United States. For more information, get Portfolio Grader’s complete analysis of ABCD stock.

H&R Block, Inc. (HRB) is bumping up its rating from a C (“hold”) to a B (“buy”) this week. H&R Block provides a wide range of financial products and services. For more information, get Portfolio Grader’s complete analysis of HRB stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.