Naimark's dilation theorem in papers and textbooks is usually stated as:
Let $E$ be a regular, positive, $B(\mathcal H)$-valued measure on $X$. Then there exists a Hilbert space $\mathcal K$, a bounded linear operator $V: \mathcal H \rightarrow \mathcal K$, and a regular, self-adjoint, spectral $B(\mathcal K)$-valued measure $F$ on $X$, such that $E(B) = V^*F(B)V$ (from Paulsen's book Theorem 4.6).
What was the original formulation of Naimark's dilation theorem? It seems conceivable that it changed over the 70+ years.
Did he assume regularity, or is this assumption coming from the later version of this theorem proved by Stinespring. Were his operator-valued measures weakly countably additive?
My trouble is that I cannot find the original paper:
Neumark, M. A., On a representation of additive operator set functions, C. R. (Doklady) Acad. Sci. URSS (N.S.), 41, (1943), 359--361
Does anyone know if this paper is legitimately online anywhere, in Russian or an English translation? As Willie Wong mentions in the comments my fall back will be interlibrary loan.