He wrote under the pseudonym Woldemar Egg .
Ernst Gotthelf Gersdorff ( also known as Ernst Gotthelf von Gersdorff or Karl Gotthelf ) ( 2 November 1804 -- 5 January 1874 ) was a German librarian , most notable for his work at the Leipzig University Library .
Ernst Gotthelf Gersdorff wrote under the pseudonym Woldemar Egg .
Ernst Gotthelf Gersdorff ( also known as Ernst Gotthelf von Gersdorff or Karl Gotthelf ) ( 2 November 1804 -- 5 January 1874 ) was a German librarian , most notable for his work at the Leipzig University Library .