@article{AUPCDM_2015_7_1_a4,
     author = {Kudryk, Taras},
     title = {Introduction to {E.} {Nelson{\textquoteright}s} internal set theory},
     journal = {Annales Universitatis Paedagogicae Cracoviensis. Studia ad Didacticam Mathematicae Pertinentia},
     pages = {59--78},
     publisher = {mathdoc},
     volume = {7},
     number = {1},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPCDM_2015_7_1_a4/}
}