@article{10_4064_fm_130_3_191_213,
     author = {Z. Ratajczyk},
     title = {A combinatorial analysis of functions provably recursive in $I\ensuremath{\Sigma}_n$},
     journal = {Fundamenta Mathematicae},
     pages = {191--213},
     publisher = {mathdoc},
     volume = {130},
     number = {3},
     year = {1988},
     doi = {10.4064/fm-130-3-191-213},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-130-3-191-213/}
}