1. Pointwise comparison principle for clamped Timoshenko beam;Bartuzel;Topol. Methods Nonlinear Anal.,2012
2. Sulle funzioni di Green d'ordine m;Boggio;Rend. Circ. Math. Palermo,1905
3. Positivity for equations involving polyharmonic operators with Dirichlet boundary conditions;Grunau;Math. Ann.,1997
4. Nichtnegativität Greenscher Functionen für u⁗+u=f in Abhängingheit vom zugrundliegenden Definitionsbereich [−L,L];Gunsenheimer,1994
5. Ordinary Differential Equations;Hartman,2002