This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Jri Nuut . et Jri Nuut eesti matemaatik ester ee bS est fotokogu Creator Heinrich Riedel PDold EE Uploaded with Mathematicians from Estonia Heinrich Riedel
Page 2023 Free-images.com. All images are Public Domain