Galerkin method operator differential equations with Lipschitz continuous coefficients E. E. Süli — 1979 Matematički Vesnik
On finite difference schemes of high order accuracy for elliptic equations with mixed derivatives B. S. Jovanović; E. E. Süli; L. D. Ivanović — 1986 Matematički Vesnik
On the rate of convergence of difference schemes for the heat transfer equation on the solutions from w 2 s , s / 2 L. D. Ivanović; B. S. Jovanović; E. E. Süli — 1984 Matematički Vesnik