@article{CM_1980__42_1_105_0,
     author = {Howard, W. A.},
     title = {Ordinal analysis of bar recursion of type zero},
     journal = {Compositio Mathematica},
     pages = {105--119},
     publisher = {Sijthoff et Noordhoff International Publishers},
     volume = {42},
     number = {1},
     year = {1980},
     mrnumber = {594485},
     zbl = {0444.03030},
     language = {en},
     url = {http://archive.numdam.org/item/CM_1980__42_1_105_0/}
}