Correction to: The Mathematical Intelligencer https://doi.org/10.1007/s00283-021-10105-6

The article “Sangaku Problems About Ellipses: Why Primary Sources Matter,” by J. Marshall Unger, was published online on August 16, 2021 with the copyright holder “Springer Nature.” With the decision to publish with Open Access, the copyright holder has changed to “The Author(s).” The original article has been revised to change the copyright holder and to add the Open Access funding note.