Nikolai Ivanovich Lobachevsky (1792-1856) (also Lobachevskii) was a Russian mathematician who had studied under Martin Bartels, a German mathematician who was a friend of Gauss. Some of the mathematical discoveries made by Lobachevsky can thus be traced back to Gauss's ideas, this leading to some questioning of the originality of his work. These and other questionable circumstances led to Tom Lehrer's cynical song carrying his name.