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In page Erica Tietze-Conrat:

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Erica and Hans Tietze were friends with many contemporary artists including Oskar Kokoschka who was commissioned to paint them in 1909, the portrait is now at the Museum of Modern Art in New York.[4] The sculptor Georg Ehrlich created two bronze busts of Hans and Erica Tietze which are now in the Österreichische Galerie Belvedere in Vienna, as well as numerous portrait drawings of Erica Tietze.[citation needed]