Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
You can help expand this article with text translated from the corresponding article in Russian. (October 2022) Click for important translation instructions.
Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Misplaced Pages.
Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article.
You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Russian Misplaced Pages article at ]; see its history for attribution.
You may also add the template {{Translated|ru|Кондратьев, Владимир Александрович}} to the talk page.
Borsuk, Michail; Kondratiev, Vladimir (2006). Elliptic Boundary Value Problems of Second Order in Piecewise Smooth Domains. North-Holland Mathematical Library. Vol. 69. North Holland. ISBN9780080461731.
