49-71. Nabben, R., & Varga, R. S. (1994). A linear algebra proof that the inverse of a strictly ultrametric matrix is a strictly diagonally dominant Stieltjes
Journal of Political Economy, 90, 1212 - 1236 "Aggregation Over Time and the Inverse Optimal Predictor Problem for Adaptive Expectations in Continuous Time"
conjecture(英語版) Is every finitely presented periodic group finite? The inverse Galois problem: is every finite group the Galois group of a Galois extension