Rapidities and observable 3-velocities in the flat Finslerian event space with entirely broken 3D isotropy. Bogoslovsky, George Yu. (2008) SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
Remarks on the ambiguity of distance determination in Friedmann's cosmological model A. Zięba (1971) Applicationes Mathematicae
Riemann-Lagrange geometrical background for multi-time physical fields. Neagu, Mircea (2001) Balkan Journal of Geometry and its Applications (BJGA)