Sources

Sources
 * BOOK~ Bruno,Leonard.Math&mathematiciation.FlaminstonHills,MI:ThomasL.Romig,1999
 * INTERNET~Maor,Eli."Euler,Leonhard"world bookstudent. world book,2012 9 May 2012
 * INTERNET~OJJ Connor, and FF Robertson ."Leonhard Euler" __Eulers Biography.__ online. Avalible __http://www.-groups.dcs.st-and .ac.uk/history/biographies/Euler.html.__ 10 May 2012
 * Patterson, Simon. Leonard Euler's Biography online avalible [] 5 May 2012