TY - JOUR AU - Mawhin, Jean AU - Szymańska-Dębowska, Katarzyna TI - Couples of lower and upper slopes and resonant second order ordinary differential equations with nonlocal boundary conditions JO - Mathematica Bohemica PY - 2016 SP - 239 EP - 259 VL - 141 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/articles/10.21136/MB.2016.17/ DO - 10.21136/MB.2016.17 LA - en ID - 10_21136_MB_2016_17 ER -