Update 4_long_div.md

docs/4_long_div.md

@@ -86,8 +86,11 @@
 2. https://en.wikipedia.org/wiki/Long_division
 3. https://www.codeproject.com/Articles/1276311/Multiple-Precision-Arithmetic-Division-Algorithm
 4. http://algolist.manual.ru/maths/longnum.php
-5. [Verma. Implementing Basic Arithmetic for Large Integers: Division](https://mathsanew.com/articles_html/23/implementing_large_integers_division.html)
-6. [Hansen. Multiple-Length Division Revisited: A Tour of the Minefield](https://surface.syr.edu/eecs_techreports/166/)
-7. [Krishnamurthy, Nandi. On the Normalization Requirement of Divisor in Divide-and-Correct Methods](https://dl.acm.org/doi/abs/10.1145/363848.363867)
-8. [Brent, Zimmermann. Modern Computer Arithmetic](https://maths-people.anu.edu.au/~brent/pub/pub226.html)
-9. https://www.geeksforgeeks.org/divide-large-number-represented-string/
+5. https://www.geeksforgeeks.org/divide-large-number-represented-string/
+6. [Verma. Implementing Basic Arithmetic for Large Integers: Division](https://mathsanew.com/articles_html/23/implementing_large_integers_division.html)
+7. [Hansen. Multiple-Length Division Revisited: A Tour of the Minefield](https://surface.syr.edu/eecs_techreports/166/)
+8. [Krishnamurthy, Nandi. On the Normalization Requirement of Divisor in Divide-and-Correct Methods](https://dl.acm.org/doi/abs/10.1145/363848.363867)
+9. [Brent, Zimmermann. Modern Computer Arithmetic](https://maths-people.anu.edu.au/~brent/pub/pub226.html)
+10. [Pope, Stein. Multiple Precision Arithmetic](https://dl.acm.org/doi/10.1145/367487.367499)
+11. [Дональд Кнут. Искусство программирования. Том 2. Третье издание. Раздел 4.3.1](https://djvu.online/file/AK1GKM4qtVd6r#p=311),
+    а также [ответы на упражнения](https://djvu.online/file/AK1GKM4qtVd6r#p=685)