@article{CM_1986__57_1_61_0,
     author = {Lassak, Marek},
     title = {A general notion of extreme subset},
     journal = {Compositio Mathematica},
     pages = {61--72},
     publisher = {Martinus Nijhoff Publishers},
     volume = {57},
     number = {1},
     year = {1986},
     mrnumber = {817296},
     zbl = {0596.52001},
     language = {en},
     url = {http://www.numdam.org/item/CM_1986__57_1_61_0/}
}