Here is a new paper (pdf) by Tanya Khonanova and Alexey Radul, entitled “Jewish Problems”:
This is a special collection of problems that were given to select applicants during oral entrance exams to the math department of Moscow State University. These problems were designed to prevent Jewish people and other undesirables from getting a passing grade. Among problems that were used by the department to blackball unwanted candidate students, these problems are distinguished by having a simple solution that is difficult to find. Using problems with a simple solution protected the administration from extra complaints and appeals. This collection therefore has mathematical as well as historical value.
For the pointer I thank Rahul R, a loyal MR reader.