In later reviews of the literature by R.L.E. Schwarzenberger and by Branko Grünbaum and G.C. Shephard in their book Tilings and patterns the work of the Russian color symmetry school led by A.V. Shubnikov and N.V. Belov was put into its proper historical context. Schwarzenberger, and Grünbaum and Shephard, give credit to Shubnikov and Belov for relaunching the field of color symmetry after the work of Heinrich Heesch and H.J. Woods in the 1930s was largely ignored. However, they criticise Shubnikov and Koptsik for taking a crystallographic rather than a group-theoretic approach, and for continuing to use their own confusing notation rather than adopting the international standard Hermann–Mauguin notation for crystallographic symmetry elements.