@article{EXMA_1995__4_2_226090,
     author = {Guckenheimer, John},
     title = {Phase portraits of planar vector fields: {Computer} proofs.},
     journal = {Experimental mathematics},
     pages = {153--165},
     publisher = {mathdoc},
     volume = {4},
     number = {2},
     year = {1995},
     zbl = {0856.34045},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMA_1995__4_2_226090/}
}