@article{CM_1969__21_1_1_0,
     author = {Williams, N. H.},
     title = {On {Grothendieck} universes},
     journal = {Compositio Mathematica},
     pages = {1--3},
     publisher = {Wolters-Noordhoff Publishing},
     volume = {21},
     number = {1},
     year = {1969},
     mrnumber = {244035},
     zbl = {0175.00701},
     language = {en},
     url = {http://www.numdam.org/item/CM_1969__21_1_1_0/}
}