@incollection{SB_1976-1977__19__105_0,
     author = {MacPherson, Robert},
     title = {The combinatorial formula of {Gabrielov,} {Gelfand} and {Losik} for the first {Pontrjagin} class},
     booktitle = {S\'eminaire Bourbaki : vol. 1976/77, expos\'es 489-506},
     series = {S\'eminaire Bourbaki},
     note = {talk:497},
     pages = {105--124},
     publisher = {Springer-Verlag},
     number = {19},
     year = {1978},
     mrnumber = {521763},
     zbl = {0388.57013},
     language = {en},
     url = {http://www.numdam.org/item/SB_1976-1977__19__105_0/}
}