@article{DCG_1989__4_6_131082,
     author = {H. Edelsbrunner and Micha Sharir and Leonidas J. Guibas},
     title = {The {Upper} {Envelope} of {Piecewise} {Linear} {Functions:} {Algorithms} and {Applications.}},
     journal = {Discrete & computational geometry},
     pages = {311--336},
     publisher = {mathdoc},
     volume = {4},
     number = {6},
     year = {1989},
     zbl = {0707.68044},
     url = {http://geodesic.mathdoc.fr/item/DCG_1989__4_6_131082/}
}