Fleer sued Topps in 1975 to break the company's monopoly on baseball cards and won, as in 1980 federal judge Clarence Charles Newcomer ended Topps Chewing Gum's exclusive right to sell baseball cards, allowing the Fleer Corporation to compete in the market. In 1981, Fleer and Donruss issued baseball card sets, both with gum. An appeal of the Fleer lawsuit by Topps clarified that Topps' exclusive rights only applied to cards sold with gum. After the appeal, Fleer and Donruss continued to produce cards issued without gum; Fleer included team logo stickers with their card packs, while Donruss introduced "Hall of Fame Diamond Kings" puzzles and included three puzzle pieces in each pack. In 1992, Topps' gum and Fleer's logo stickers were discontinued, with Donruss discontinuing the puzzle piece inserts the following year. With the issuance of a very popular and rare (compared to other sets at the time) set in 1984, Donruss began to take hold as one of the most popular card brands in competition with Topps. In particular, several rookie cards in the 1984 Donruss set are still considered the most desirable cards from that year of any brand (especially the Don Mattingly rookie card). Also in 1984, two monthly price guides came on the scene. "Tuff Stuff" and "Beckett Baseball Card Monthly", published by Dr. James Beckett, attempted to track the approximate market value of several types of trading cards.