@article{IM_1981__63_142787,
     author = {Leo Jonker and David Rand},
     title = {Bifurcations in {One} {Dimension.} {II.} {A} {Versal} {Model} for {Bifurcations.}},
     journal = {Inventiones mathematicae},
     pages = {1--16},
     publisher = {mathdoc},
     volume = {63},
     year = {1981},
     zbl = {0475.58015},
     url = {http://geodesic.mathdoc.fr/item/IM_1981__63_142787/}
}