puzzle designs by Tony Fisher, including the Golden Cube, and Oskar van Deventer, including the Gear Cube. More recently he licensed and re-released designs from other manufacturers, such as Dogic. Mèffert also created his own version of sudoku. In addition to the standard sudoku rules, the two major diagonals must also contain the numerals from 1 to 9. Additionally, a Chinese magic square is hidden somewhere in the solution. He named this puzzle Kokonotsu, Japanese for nine. Biography Mèffert was born in Wernigerode in the Harz Mountains of Germany on 28 November 1939. Mèffert was the son of Otto Oscar Wilhelm Rudolph Mèffert and Emmy Johanna Frieda Von-Vorkauf. He was educated in Heidelberg, Germany, Geelong, Australia, and Bern, Switzerland. He resided in Hong Kong since the early 1980s, as well as spending much time in Australasia researching human and animal nutrition. He was married to Jing Mèffert; they have three children: Michelle, Andrew and Ulrich, and at least two grandchildren. Mèffert died 30 April 2022 due to complications while recovering from COVID-19. References 1939 births 2022 deaths Puzzle designers Toy inventors German designers People from Wernigerode