I'm having some trouble identifying a reference Landau and Lifshitz make in volume 3 - non-relativistic quantum mechanics - of their Course of theoretical physics. This is the page from the Oxford, Pergamon, 1977 edition:
There isn't a bibliography either at the end of the chapter or the book, and other references are usually well identified in footnotes. I know it's a long shot to identify and obtain a copy of this article (in English), but I would definitely like to have a look at it. It appears to be the original publication of Landau's method of complex-contour integration to find WKB-approximation matrix elements.