From 1973 to 1986 the Iyanaga Prize was awarded for the best mathematical research done by a Japanese mathematician under the age of 40. Since 1987 the Iyanaga Prize has been replaced by the Spring Prize and Autumn Prize for 2 of the best Japanese mathematicians under the age of 40. List of prize winners, Mathematical Society of JapanArchived 2010-12-26 at the Wayback Machine
From 1973 to 1986 the Iyanaga Prize was awarded for the best mathematical research done by a Japanese mathematician under the age of 40. Since 1987 the Iyanaga Prize has been replaced by the Spring Prize and Autumn Prize for 2 of the best Japanese mathematicians under the age of 40. List of prize winners, Mathematical Society of JapanArchived 2010-12-26 at the Wayback Machine