- eBookThe Geometry of GeodesicsHerbert Busemann
- eBookConvex SurfacesHerbert Busemann
- eBookProjective Geometry and Projective MetricsHerbert Busemann
- eBookMetric Methods of Finsler Spaces and in the Foundations of Geometry. (AM-8)Herbert Busemann
- eBookSerien: Dover Books on MathematicsRobert Gilmore
- eBookSerien: Annals of Mathematics StudiesRichard Taylor