@article{AM2_1975__12_136488,
     author = {J.M. Cushing},
     title = {Extremal {Tests} for {Scalar} {Functions} of {Several} {Real} variables at {Degenerate} {Critical} {Points.} {(Short} {Communication).}},
     journal = {Aequationes mathematicae},
     pages = {109--110},
     publisher = {mathdoc},
     volume = {12},
     year = {1975},
     zbl = {0316.26008},
     url = {http://geodesic.mathdoc.fr/item/AM2_1975__12_136488/}
}