. . . "1894Z"^^ . . "Heinz Hopf (19 November 1894 \u2013 3 June 1971) was a German mathematician who worked on the fields of topology and geometry. He was one of the greatest mathematicians of the XX century."@en . . . . "Hopf, Heinz"@en . . . . "Heinz Hopf"@en . . "Swiss mathematician" . . "1971-06-03Z"^^ . . . . . . . . . . . . . . "1971Z"^^ . . "1894-11-19Z"^^ . . . .