On Unitary Representations of the Inhomogeneous Lorentz Group
1.Did u fully browse the internet ...?This is a really old article and there are slim chances u find it online.What journal contains it?If it's APS (Phys.Rev.Rev.Mod.Phys.Phys.Rev.Lett),u can use PROLA,but only if u have "account" (either u or your univ.pays money to them).
2.I'm sure in Beijing there must be a library which would have the article.You can ask for a xerox copy.
I'm sure it's this article:
Wigner,E.P.,"On the unitary representations of the inhomogenous Lorentz group",Ann.Math.,40,149-204,1939.
P.S.Just like PROLA,u have to pay
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