@article{dougall:1907:vtg,
    author = {Dougall, John},
     title = {On {V}andermonde's theorem, and some more general expansions},
   journal = {Proc. Edinburgh Math. Soc.},
    volume = {25},
      year = {1907},
     pages = {114–132},
     zblno = {38.0313.01}}