Germany's former defense minister has apologized to a Swiss journalist for failing to credit her as a source for parts of his doctoral thesis.
Karl-Theodor zu Guttenberg acknowledges having used extracts of an article by Klara Obermueller without proper academic citation.
Extracts of his apology to Obermueller were published Sunday in the Zurich weekly NZZ am Sonntag that first ran her article in 2003.
The paper's editor, Felix E. Mueller, says the apology was an "overdue, right and positive step."
Guttenberg resigned March 1 after the plagiarism allegations threatened to become a liability for Chancellor Angela Merkel's conservatives in upcoming regional elections.