| An infinite continuous model which derives from a finite discrete model describing the time evolution of the density of firms | 2 | 0.43 | 2002 |
| The nonlinear integro-partial differential equation describing the logistic growth of human population with migration | 6 | 1.13 | 1999 |
| The Cauchy problem for the system of equations describing migration motivated by regional economic disparity | 8 | 2.16 | 1998 |
