Existence in mathematics
Compositio Mathematica, Volume 20  (1968), p. 70-82
@article{CM_1968__20__70_0,
     author = {Goodstein, R. L.},
     title = {Existence in mathematics},
     journal = {Compositio Mathematica},
     publisher = {Wolters-Noordhoff Publishing},
     volume = {20},
     year = {1968},
     pages = {70-82},
     zbl = {0162.30901},
     mrnumber = {224413},
     language = {en},
     url = {http://www.numdam.org/item/CM_1968__20__70_0}
}
Goodstein, R. L. Existence in mathematics. Compositio Mathematica, Volume 20 (1968) , pp. 70-82. http://www.numdam.org/item/CM_1968__20__70_0/