@article{TIMM_2003_9_1_a18,
     author = {R. Haberman and D. C. Diminnie},
     title = {On the dynamic unfolding of a~saddle-center bifurcation and the change in the action},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {159--164},
     year = {2003},
     volume = {9},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2003_9_1_a18/}
}