@article{JRAM_1969__236_150935,
     author = {K.F. Barth and W.J. Schneider},
     title = {Exponentiation of functions in {MacLane's} class {A.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {120--130},
     publisher = {mathdoc},
     volume = {236},
     year = {1969},
     zbl = {0175.07801},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1969__236_150935/}
}