@article{AIHPA_1986__45_3_327_0,
     author = {Gudder, Stanley},
     title = {Logical cover spaces},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {327--337},
     publisher = {Gauthier-Villars},
     volume = {45},
     number = {3},
     year = {1986},
     mrnumber = {868530},
     zbl = {0612.03026},
     language = {en},
     url = {http://www.numdam.org/item/AIHPA_1986__45_3_327_0/}
}