I'm researching the isometric dips of the hyperbolic plane and in particular I'm interested in reading the results of Rozendorn who proved that the hyperbolic plane is isometrically immersed in $\mathbb R^5$. The demonstrations that I have been able to find in this regard, for example in Gromov's book, do not go with Rozendorn's initial idea, I say it because he demonstrates it in: but I have not been able to locate that article anywhere. Does anyone know where I can find it? or maybe someone knows other results in the same line of the original demonstration of him?

From what I have been able to read, the proof that Rozendorn gives is based entirely on the functions that Blanusa gives in this Article in which he proved that the hyperbolic plane is isometrically embedded in $\mathbb R^6$.