@article{10_4153_CJM_1967_105_0,
     author = {Duff, G. F. D.},
     title = {Differences, {Derivatives,} and {Decreasing} {Rearrangements}},
     journal = {Canadian journal of mathematics},
     pages = {1153--1178},
     year = {1967},
     volume = {19},
     number = {1},
     doi = {10.4153/CJM-1967-105-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1967-105-0/}
}