Dutch museums have published two pages of Anne Frank's diary that had previously been hidden behind a layer of sticky brown paper.
The Anne Frank House Museum said at a presentation that it, and several Dutch historical institutes, were able to reproduce the lost pages after years of study by shining a light through them and photographing them in high resolution.
One of the pages contains some dirty jokes. On the other page, she wrote what she would answer if someone asked a young girl for sex education.
Researchers say that the pages tell more about Anne Frank as a girl, teenager and writer.
Frank and her family hid from the Nazis in a secret annexe in a house in Amsterdam during World War II but were discovered in 1944.
She died aged 15 at Bergen-Belsen concentration camp in 1945.
Her diary was published two years later and has been read worldwide and translated into at least 60 languages.