@article{oai:ynu.repo.nii.ac.jp:00004786,
 author = {Nishimura, Takashi},
 issue = {2},
 journal = {Pacific journal of mathematics},
 month = {Aug},
 note = {application/pdf, We introduce map germs of pedal unfolding type and the notion of normalized Legendrian map germs. We show that the fundamental theorem of calculus provides a natural one-to-one correspondence between Whitney umbrellas of pedal unfolding type and normalized swallowtails.},
 pages = {459--471},
 title = {Whitney umbrellas and swallowtails},
 volume = {252},
 year = {2011}
}