These are things named after Felix Klein (1849 – 1925), a German mathematician.
Beltrami–Klein model
Cayley–Klein metric
Klein bottle
Klein configuration
Klein four-group
Klein geometry
Klein model
Klein quadric
Kleinian group
Kleinian integer
Kleinian ring
Schottky–Klein prime form
The Felix Klein Protocols
Felix Klein medal, named after the first president of the ICMI (1908–1920), honours a lifetime achievement in mathematics education research.
The Klein project of the IMU and ICMI aims to produce a book for upper secondary teachers that communicates the breadth and vitality of the research discipline of mathematics and connects it to the senior secondary school curriculum.
