التكامل

1- Stillwell, J. , Mathematics and Its History, Springer,  1989 , p. 131
2- Katz, Victor J. , A History of Mathematics: An Introduction, Addison-Wesley, 2009, p. 785
3- Cajori, F., A History Of Mathematical Notations Volume II, Open Court Publishing (1929),  p.p. 249-250