@article{PORMA_1948__7_4_114666,
     author = {Hu, Sze-Tsen},
     title = {On the {Whitehead} group of automorphisms of the relative homotopy groups},
     journal = {Portugaliae mathematica},
     pages = {181--206},
     publisher = {mathdoc},
     volume = {7},
     number = {4},
     year = {1948},
     mrnumber = {0033526},
     zbl = {0035.38902},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1948__7_4_114666/}
}